glossary for geospatial analysis - microimages

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Glossary

Glossary forGeospatial Analysis

with the

TNT products

Glossary for Geospatial Analysis

MicroImages’ Scientific Writers, 9 May 2012© MicroImages, Inc., 1990–2012

Before Getting StartedTNTmips is MicroImages’ flagship product for geospatial analysis. TNTmips isused in more than 150 nations around the world for geographic informationanalysis (GIS), advanced image processing, CAD, desktop cartography,electronic atlas preparation, and other spatial database management andvisualization applications. TNTmips offers a level of data and process integra-tion that is unmatched in any other professional system. And you can useTNTmips on Windows and Macintosh computers with exactly the same set offeatures and user interface on each platform. TNTmips is the most technicallyadvanced and easy to use professional system on the market.

This Glossary defines the specialized technical vocabulary that is associatedwith TNTmips. The staff of MicroImages uses many of the terms included herewith slightly different meanings than those in general usage. These definitionsestablish a common vocabulary for communicating with other TNTmips usersand MicroImages’ technical support staff. Because this glossary was compiledbeginning in 1990, some of the terms may seem distinctly out of date, such asoptical disk and WORM drive. Think of this glossary as an historic referencein that respect.

Definitions credited to (Random House) are from The Random House Dictio-nary of the English Language, Second Edition, Unabridged.

More Documentation This booklet is adapted from the glossary in the TNTmipsreference manual. You may wish to consult the reference manual for additionalinformation.

TNTmips Pro, TNTmips Basic, and TNTmips Free TNTmips comes in threeversions: TNTmips Pro, TNTmips Basic, and TNTmips Free. HyperIndex Linkeris available only to customers using TNTmips Pro. If you did not purchase theprofessional version (which requires a software license key), you are usingTNTmips Free or TNTmips Basic, which limit the size of your project materials.

MicroImages’ web site is your source of the newest tutorial booklets on awide variety of topics in geospatial science. You can download the tutorialbooklets, an installation guide, sample data, and the latest edition of the TNTproducts.

http://www.microimages.com


— A —AAT: ARC/INFO Coverage attribute table;

created when vector objects are exportedto ARC files.

absolute colorimetric rendering: A ren-dering intent in which the colors in thesource gamut (displayed image) that areavailable in the destination gamut(printer) are rendered exactly as they areand colors outside the destination gamutare replaced by the nearest available colorat the outer limit of the destinationgamut. White may or may not be repro-duced exactly.

accelerator: A key or key combination thatinvokes the action of some component(like a push button or menu selection)regardless of the position of the locationcursor. An accelerator can activate amenu selection even if the menu is notopen.

accuracy: The measurement for an X-Ydigitizing tablet of how close the reportedcoordinates for any given point come tothe point’s actual location. Accuracy isstated in terms of the possible distancefor error (for example, ±.01 or ±.025).

active area: The area on an X-Y digitizingtablet that is sensitive to the pointingdevice.

active element: The last vector, CAD, orTIN element added to a selection set insingle select mode. If the selection set isestablished using a selection tool that al-lows multiple elements to be selected atone time, such as the rectangle or circletool, the active element is the elementwith the lowest element number amongthose selected.

additive color: Colors perceived by thehuman eye that are created by mixingdifferent colors of light, or visible radia-tion are produced in an additive manner.The colors of the images produced on acolor display screen or by a color projec-tion onto a white screen are examples ofadditive color. When all wavelengths, orcolors, of visible light are mixed, whitelight is produced. That all visible colors

are present in white light is easily demon-strated using a prism, which separateswhite light into the spectrum of colors ofwhich it is composed. White light canalso be produced by mixing complemen-tary colors. Absence of radiation or rela-tively low radiation at all wavelengths ofhuman visual sensitivity will yield black.A predominance of radiation in a particu-lar range of wavelengths will yield a colorwhose intensity is proportional to thelevel of radiation. (See also: subtractivecolor)

aerial photograph: see airphoto.

affine: Transformation of geodata that mapslines to parallel lines and finite points tofinite points.

agronomy: The study of crop and soil sci-ences including crop breeding, genetics,and cytology; plant molecular biology andplant molecular genetics, crop physiol-ogy and metabolism; crop ecology, pro-duction, and technology; turf grass; cropquality and utilization, agroclimatologyand agronomic modeling; soil physics; soilchemistry; soil microbiology; soil fertil-ity and plant nutrition; soil genesis, mor-phology, and classification; soil mineral-ogy; and soil management.

airphoto: A photograph taken verticallyfrom the air. Any type of camera may beused, but single-lens frame cameras aremost commonly used. Airphoto imagescan be available to users as paper prints,transparent film, or digital computer files.An airphoto includes significant horizon-tal displacement introduced by cameracharacteristics, tilt, nearness to the tar-get scene, and variations in elevation ofthe target terrain.

airslide: A 35mm slide taken vertically fromthe air.

airvideography: The growing field of mak-ing measurements from digitized framesof vertical airvideo images. These mea-surements can be used for managing agri-cultural and natural resources, making taxassessments, and monitoring environmen-tal degradation among other uses.

airvideo image: An image acquired verti-cally with a color, monochrome, or color-infrared video camera and recorder.


albedo: “The ratio of the light reflected bya planet or a satellite to that received byit” (Random House). This definition canbe generalized to any object, such as apart of the earth’s surface or atmosphere,a leaf, a soil element, and so on.

algorithm: A numerical scheme applied toreach a solution of a problem.

aliasing: (referring to a graphic display oflines) A line that is drawn digitally, cell bycell, with fixed, uniform color and inten-sity is said to be aliased. The cells areeasily resolved by the observer’s eye sothe line is seen to have a jagged, stair-stepappearance. (See also: anti-aliasing.)

allocation: The movement of materials intoor out of a number of centers, all of whichserve the same purpose, such as schools,fire stations, or warehouses. The Net-work Analysis process includes an allo-cate mode.

alphabetic: A written language that uses afixed, ordered set of phonetically-relatedcharacters is said to be alphabetic. MostWestern European languages are alpha-betic (Latin-based), as are Greek, Hebrew,Arabic, Russian, Turkish, and Indian.Modern Korean (Hangul) is an alphabeticreplacement for Chinese-based characterwriting which was used until the 1500’s.

Modern non-alphabetic languages includeChinese and Japanese, in which charac-ters may be syllabic constructs histori-cally derived from pictographic arche-types. While they use a basic set of char-acters (a few thousand) for most writing,the character set is not strictly limited toa fixed number of characters.

AM/FM: Automated Mapping and FacilitiesManagement. A geographic informationsystem designed for the optimal process-ing of information about utilities and in-frastructures, such as power lines and wa-ter and telephone networks.

analog: Information stored and processed assignal intensity or other measurement ofa continuous physical variable. Analoginformation processing translates and rep-resents slight increments in data easilyand conveys information by relative po-sition without relying on the numeric valuenecessary to convey the same informa-tion digitally. For example, the second

hand on an analog watch “sweeps” aroundthe dial and you can tell time on an ana-log watch even if it has no numbers onthe face. Another example is a thermom-eter that displays temperature using aneedle or liquid can indicate fractions ofa degree, as well as provide informationabout relative warmth by the position ofthe dial or height of the liquid. On theother hand, this continuous analog in-formation is harder to copy, store, ma-nipulate and reproduce dependably. Any-one who has ever listened to a copy of acopy of a copy of a cassette tape hasfirst-hand knowledge of analog informa-tion degradation. For this reason, muchanalog information (video, audio, or fieldand laboratory measurements of tem-perature, pressure, voltage, radiation, andso on) is converted to its digital equiva-lent. (See also: digital, digitizer)

angle impedance: The opposition to flowaround a turn in network analysis. Angleimpedance is determined by node prop-erties and your choice of lines for ap-proaching or leaving the node.

anisotropy: A distribution of point geodatain which the probability of encounteringother points starting from any givenpoint is not equal in all directions. Anisot-ropy can apply over short or long dis-tances.

ANSI: American National Standards Insti-tute is a national coordinator of volun-tary standards activities and acts as anapproval organization and clearinghousefor consensus standards in the USA.ANSI works closely with internationalorganizations, particularly ISO, for thedevelopment and approval of interna-tional standards.

antarctic circle: A small circle of the earthparallel to the equator drawn on maps at23° 27' from the south pole (66° 33' S).The exact location of the antarctic circlevaries slightly since it is defined by thesun’s furthest southern declination (po-sition at winter solstice) from year toyear.

anti-aliasing: (referring to a graphic dis-play of lines) Anti-aliasing removes orgreatly reduces the jagged, stair-step ap-pearance of a digital line. This stair-


stepping is caused by plotting a uniformcolor and intensity line on a display de-vice whose minimum resolution or cellsize is easily resolved by the observer’seye.

Anti-aliasing smoothes out the jaggededges of the line by filling in some of theintermediate and flanking cells in lower-intensity colors. (See also: aliasing)

API: An Application Program Interface is aset of system calls or routines for appli-cation programs to access services fromoperating systems or other programs.APIs are fundamental to client/servercomputing.

API key: A mechanism used by Google toauthorize users to access the GoogleMaps API to embed the Google Mapsgeoviewer in a web page.

APPLIDAT: A unique combination of SMLscripts and Project File geospatial datacreated in TNTmips. An APPLIDAT

(APPLIcation plus DATa) can belaunched from a desktop icon that opensthe preselected geodata and presents acustom icon toolbar.

arbitrary georeference: A georeferencethat uses a matrix rather than controlpoints. Raster, vector, CAD, or TINobjects can have an arbitrarygeoreference. An arbitrary georeferenceis created when an object with nogeoreference is used as a reference layerfor creation of a new object in TNT’sEditor or the new object is created in aprocess such as Auto-Trace from a non-georeferenced object. An arbitrary geo-reference allows you to correctly displayrelated objects together. This type ofgeoreference is currently referred to inthe TNT products as local engineering.

archive: A preserved collection of historicalinformation, such as a backup of yourdata.

ARC/INFO: A vector-based Geographic In-formation System (GIS) developed andmarketed by ESRI, Inc. for use on work-stations.

ARC/INFO extent file: The name of thedata file used by ARC/INFO which con-tains arc, node, and polygon data ele-ments.

arcsecond: “The sixtieth part of a minute ofangular measure often represented by thesign “, as in 30”, which is read 30 sec-onds” (Random House). (See also: de-gree, minute.)

arctic circle: A small circle of the earth par-allel to the equator drawn on maps at 23°27' from the north pole (66° 33' N). Theexact location of the antarctic circle var-ies slightly since it is defined by the sun’sfurthest northern declination (position atsummer solstice) from year to year.

Area correlation: A DEM extraction methodthat methodically traverses a pair of ste-reo images, working from the initial setof correlation points supplied by the user,and building a correlation model from newpoints of correlation that it finds.

areal extents: Size, or magnitude, of an arearepresented digitally as features in eitherimage or geometric format. Areal ex-tents of component files are recorded inLDS files when they are generated by aTNT process.

ASCII: American Standard Code for Infor-mation Interchange (pronounced“askee”). The 7-bit (128 characters) usedas a computer’s alphabet. The Latin al-phabet character set encoded into digitalvalues between 0 and 127 includes lower-case and uppercase letters, the numerals0–9, English punctuation marks, specialsymbols (such as @#$%^&*) and non-displaying characters often used as printercontrol codes. The eighth bit, giving val-ues from 128 to 255, is used in a non-standard fashion and is not part of thestandard ASCII code. PCs normally havethe “extended” character set in their sys-tem font for digital values from 128 to255. The characters used for values from128 to 255 for TNTmips display screenfonts are unpredictable but can be dis-played in the font style window. Somefonts have no characters in this rangewhile others have characters for some orall of these values. ASCII is a propersubset of Latin-1, Unicode, and ISO10646, which are the 1-byte, 2-byte, and4-byte standards for international char-acter encoding.

The term “ASCII file” is often used tomean a text-only file. Documents in


most word processors are not text-onlyfiles, since they include header informa-tion and formatting characters. Howevermost word processors have an export orprint-to-file utility that will convert adocument into a text-only ASCII format.

ASCII file: A text-only file. Documents inmost word processors are not text-onlyfiles, since they include binary header in-formation and formatting characters.However most word processors import so-called ASCII files and have an Export,Save/Text-only, or print-to-file utilitythat converts a document into an “ASCII”format. However, these files are not trueASCII files because they may include thecharacters from 128-255. The charac-ters in this range are different betweenplatforms such as PCs and Macintoshesand even from font to font with a plat-form, and are not part of the standard 7-bit ASCII code. (See also: ASCII.)

ASCS: Agricultural Stabilization and Con-servation Service. Merged with other ag-ricultural agencies in 1994 to create theFarm Service Agency.

aspect: A parameter that is associated with afeature of a topographic or other threedimensional surface. Aspect is the com-pass direction (usually from north) forthe perpendicular to the tangent to thesurface at some selected point. Aspecttells which direction a surface slopes mea-sured in degrees from North in a clock-wise direction.

aspect ratio: The ratio of horizontal scaleto vertical scale for printing or display.For graphics and image processing, squarecells/pixels are best (aspect 1:1). Somedisplay devices have a non-square aspect,which causes images to appear stretchedor distorted. Standard broadcast video hasan aspect ratio of 4:3, which must be cor-rected in any framegrabbing or other digi-tization process.

Assemble Geomashup: The Assemble Geo-mashup process in TNTmips (Main /As-semble / Geomashup) allows you to mashupyour own tilesets with geodata layers fromremote sources for viewing in a webbrower. You can choose base maps, over-lay layers, the web mapping API to use,and the map controls to include. At any

time during the assembly of yourgeomashup you can immediately previewit in any popular Windows or Macbrowser (Firefox, Safari, Internet Ex-plorer, Chrome, and Opera) to test thecurrent design and operation. The pro-cess also creates the HTML file with Java-Script required for your current layerchoices and tools.

assignment statement: A line in a queryor script that changes the value of a styledrawing variable. Example: size = 5. Thatstatement changes the value of the sizevariable to 5. (The size variable con-trols the size at which node elements aredrawn). Assignment statements may beused in vector display and several otherprocesses that let you assign drawingstyles by query.

attribute: A piece of information describ-ing an element in a coordinate data ob-ject or a raster cell. Each element in avector, CAD, or TIN object may be as-signed one or more attributes. Elementattributes include internal informationand information in an associated data-base. Attributes can include such qualitiesas drawing style, element number, andclassification category, such as “inter-mittent stream” or “wetland.”

attribute table: A tabular object containingrecords and fields, or rows and columns.Each record, or row, represents one ormore geographic features and each field,or column, represents one attribute ofthose features.

AutoCAD: The most popular commercialComputer Aided Design (CAD) softwarepackage written and distributed byAutodesk, Inc. This software supportsthe same display boards as TNTmipswith its own display drivers.

autocorrelation: “The correlation of anordered series of observations with thesame series displaced by the same num-ber of terms” (Random House).

auto-correlogram: A process inHyperspectral Analysis. The Auto-Correlogram process provides an esti-mate of the spatial-spectral variabilityof the hyperspectral image on a pixel bypixel basis.

auto-name: Name for output file that is


automatically assigned based on input oroutput object//file (depending on process,e.g., tile files use easting and northingcoordinates of tile’s lower left corner,output objects from vector merge areeach named merge and appended by anumber if multiple output objects arewritten to the same file).

AVHRR imagery: Advanced Very HighResolution Radiometer imagery producedby NOAA satellites.

AVIRIS imagery: Airborne Visible/InfraRedImaging Spectrometer imagery. Multi-spectral images of approximately 240coregistered spectral bands collected byNASA aircraft.

azimuth: The angle defined by the inter-section of a map’s central line of projec-tion with any meridian. If a map projec-tion uses a central line that is oriented totrue north, such as a standard meridian,the azimuth angle is zero.

azimuth angle: Angular displacement fromNorth.

azimuthal projections: (also known asPlanar Projections) A class of map pro-jections that are constructed by placinga flat planar surface tangent to a singlepoint on the globe, or by placing theglobe to an intersecting (secant) plane.With azimuthal (or planar) projections,lines of equal distortion are concentricaround the point of tangency or the cen-ter of the circle of intersection. Mostazimuthal maps do not have standard par-allels or standard meridians. Each maphas only one standard point: the center.Thus, the azimuthal projections are suit-able for minimizing distortion in a some-what circular region, such as Antarctica,but not for an area with predominantlength in one direction. Azimuthal pro-jections include Orthographic, Stereo-graphic, Gnomonic, Lambert AzimuthalEqual-Area, and Azimuthal Equidistant.

azimuth spacing: The linear distance orimage scale in the along-track dimen-sion, which is perpendicular to the rangedirections in a radar image. The resolu-tion of a synthetic aperture radar (SAR)image in the azimuth direction is con-stant and independent of range.

— B —backup: A copy of a file, set of files, or whole

disk for safekeeping in case the original islost or damaged.

band or spectral band: A range of wave-lengths of electromagnetic radiation.Remote sensing devices commonly col-lect images in discrete bands, such as vis-ible red, green, and blue, and the invisiblenear-infrared.

band interleaved: A type of geodata stor-age and reading for multiple bands. Thegeodata is stored and read line by line.That is, the first line of the first band isfollowed by the first line of the secondband, the first line of the third band, andso forth through all bands . Then thenext line stored is line two of the firstband followed by line two of the secondband and so forth through all lines withinall bands.

band mapping: A spectral matching methodin Hyperspectral Analysis. The BandMapping method compares unknownspectra that you are analyzing to spectrain a reference spectral library on the basisof the positions and relative depths ofabsorption features.

band trailer bytes: Some image bands havetrailer information attached to the endof each band image. In the User-definedRaster Import process a user must tell theimport process the length of this trailerin bytes so that the import process canimport the trailer information correctly.

band variance: One of three noise statisticsplots that can be produced in theHyperspectral Analysis process. The bandvariance plot shows the proportion ofthe variance, or noise, that can be attrib-uted to each input band.

bandwidth: A measure of the volume of datathat can flow through a communicationslink, or throughput. Bandwidth is mea-sured in kilobits or megabits per second.(Kb/s, Mb/s). Also, a section of the elec-tromagnetic spectrum between two fre-quencies. For example, AVIRIS collects


224 contiguous spectral bands with a band-width of 0.10 micrometers.

barrier: A node that can not be crossed inthe Network Analysis process.

basin: (watershed analysis) The area drain-ing to any particular point in the land-scape (called a seed point); a subwatershedor subcatchment. Standard basins in thewatershed process are generated usingstream junctions as seed points, so a stan-dard basin is the area drained by a particu-lar tributary system of the main stream.

batch: A DOS batch file is a text file with theextension .BAT that contains one DOScommand on each line. When you enterthe name of the batch file at the DOSprompt, the system performs each com-mand in turn.

batch job: (TNTmips) A process or sequenceof processes that is set up with Job Man-ager or another process to run unattended,requiring no user interaction or supervi-sion.

bathymetry: The science of measuring ocean,sea, and lake depths.

baud rate: The speed of data transmissionbetween a computer and other devicesmeasured in pulses per second.

Bézier curve: A polynomial curve boundedby four points, which form a “boundingbox.” Manipulating the position of thebounding points lets a user stretch andposition a smooth curved line in the de-sign of a graphic shape, such as the irregu-lar curving outline of a font character.

bilinear interpolation: A mathematicalmethod for interpolating a new cell’s valuewithin a 2 x 2 neighborhood of cells. Bi-linear interpolation is used in resamplinga raster object to create a new raster ob-ject with a different cell size, orientation,or internal geometry. (See also: interpo-lation.)

binary: A base 2 number system that usesonly the data values “0” and “1.” Eachplace represents a power of 2, so, for ex-ample, the decimal number 6 is representedin base 2 as 110 (= 1x4 + 1x2 + 0x1).

binary raster object: A raster whose cellscontain only the values “0” (typically dis-played as black) or “1” (white). Binary

raster objects usually store a scan of blacklines on white paper, the results ofthresholding a byte-oriented raster ob-ject into two data ranges, a threshold ofa particular color range, or a data mask.

Bing Maps: Bing Maps is a web mappingservice provided by Microsoft with streetmaps for many cities worldwide.

Bing Maps Custom Tile Overlay: “Cus-tom Tile Layer” is the name Bing Mapsuses to refer to the stucture of the tilesetsthat its API for an overlay. It conceptu-ally emulates the way in which Microsoftstores its proprietary Bing Maps road andaerial layers accessible over the Internet.Tiles for areas of the source image thatare to be treated as completely coveredby the tile are usually *.jpg. Tiles are*.png where the area covered overlapsthe regular or irregular outer edge edge ofthe source image or an inner edge formissing internal areas. All tiles can alsobe *.jpg or all *.png depending upon thedesired appear of the source image in theapplication.

biomass or total biomass or total plantmaterial: The amount of plant mate-rial per unit of ground area, recorded ei-ther as wet weight or dry weight. It isusually expressed in grams per squaremeter, tons per acre, or metric tons perhectare.

bit: The smallest unit of computer datahaving a single value of either “1” or“0”. A contraction of the two words“Binary” and “digit”. Binary data is 1-bit data. Computers normally manipu-late bits at least 8 at time. A group of 8bits is called a byte. A computer’s pro-cessing power is often measured by thenumber of bits it handles at once. Theearliest PC’s were 8-bit machines. Morerecently processors and data structuresfor 16-bit, 24-bit and 32-bit data havebecome common.

bitmapped font: A font specification inwhich each character is described pixelby pixel for a particular font size. Thus,bitmapped fonts do not rescale easily: atsmaller sizes, pixels are left out, and atlarger sizes, pixel reduplication causes ajagged, blocky, low-resolution appear-ance. (See also: outline font.)


bits per pixel or pixel depth: The numberof data bits each pixel represents. In 8-bit contexts, the pixel depth is 8, andeach display pixel can be one of 256possible colors or shades of gray. With a24-bit raster (or with three coregistered8-bit rasters) the pixel depth is 24, and16,777,216 colors are possible.

BLM: Bureau of Land Management of theUSDI.

BLOB: Bianary Large OBject. The datatype of a field in an RDBMS table thatcan store large image or textual data asattributes.

block: A block is a grouping of CAD ele-ments and attributes that can be manipu-lated as a whole. All CAD objects con-tain at least one block, the Main Block.When a block (such as the detail for adoor frame) is used multiple times in adrawing, the block description is storedonce, and each insertion point refers tothat source.

block insertion element: A block that isinserted into another CAD block and,thus, acts as an element.

board: An electronic circuit board installedin a microcomputer to add hardware fea-tures. (See also: display board.)

Boolean expression: A type of expressionthat reduces to a logical (true or false)condition that contains logical expres-sions (e.g., Flowrate > 50) and Booleanoperators.

Boolean operators: An operator that speci-fied how to combine simple logical ex-pressions into complex logical expres-sions, such as OR, AND, and NOT. Forexample, Flowrate > 50 AND Depth <100. Exclusive Or (XOR) and AND NOTare also Boolean operators.

boxcar classification or boxcar interpre-tation: The simplest form of auto-mated image interpretation wherebythree data ranges are selected for threecoregistered images (like red, green, andblue). The three data ranges define aboxcar shape if plotted on three dimen-sional perpendicular axes that representpossible data values in red, green, andblue. The ranges are usually selected torepresent the color variation in the three

rasters for a feature of interest (like allthe dark brown areas representing baresoil).

All of the data triplets in the three rasterobjects are tested to determine if theyrepresent a cell inside the boxcar. All theinside cells may then be displayed or oth-erwise recorded as “classified.”

Boxcar classification is not restricted tosets of three rasters. It may be used withany number: using 2 rasters designs a 2-dimensional “boxcar” test in a 2-dimen-sional space, and using “n” rasters definesan n-dimensional “boxcar” test in n-di-mensional space.

box cursor or location box: Marks the fo-cus for keyboard activity in a window.

breakline: A linear feature that controls thesurface behavior of a TIN in terms ofsmoothness and continuity. Breaklinesare always maintained as linear featuresin a TIN.

brightness: The physical property indicat-ing how much electromagnetic radiationis being reflected or radiated by a chosenpoint. Brightness is similar to the HISproperty of Intensity, and is used in theHBS color model. Brightness is also theproperty computed from Landsat MSS orTM images by Kauth’s greenness, bright-ness, wetness transformations. (See also:HBS, HIS.)

BSD license: A family of permissive, freesoftware licenses modeled after the Ber-keley Software Distribution license.

BSpline : A curved smoothing that can beapplied to a line. A BSpline is calculatedby a polynomial equation. Different typesof BSplines, such as Cubic BSpline andQuadratic BSpline, can be calculated fromdifferent types of polynomial equations.

bubble: A small island (often just a cell ortwo) of background color in the streamof a thinned, binary line in a raster. Bubblesare artifacts of the thinning process andresult from binary lines that include un-noticed cells of the background color af-ter thresholding. Bubbles must be repairedby raster editing or else the automaticvectorization process will create small,incorrect polygon elements from them.

buffer: A portion of computer memory set


aside for quick temporary storage. A bufferis commonly used to store data on its wayto or from a hardware device such as adisk drive. The buffer lets the computer“save up” access operations and not beslowed down by waiting on the hardwareto respond at every step.

buffer zone: A border area that acts as abarrier separating or surrounding an areadesignated for special protection. Somestates have legislated buffer zones aroundcertain wetlands to prevent damage to thelocal ecosystem.

bug: An error in a computer program or in apiece of electronics that causes it to mal-function. MicroImages prefers to callthese by their real name—errors.

building points: Creating and/or addingpoints in a vector object from importedcoordinate data (like text files that con-tain pairs of coordinates, or database fileswith fields representing pairs of coordi-nates).

bus: The circuit channel or path a computeruses to move data and send signals be-tween devices. A microcomputer’s busarchitecture determines what kinds of pe-ripheral circuit cards can be plugged intoits expansion slots. DOS and OS/2 com-puters have four varieties of bus architec-ture: PC, AT (also called ISA), EISA, andMicro Channel. The original PC bushandles 8-bit data. The AT bus doubledthe data width to 16 bits and became theindustry standard (thus ISA, for IndustryStandard Architecture). IBM introducedthe PS/2 with a proprietary bus, the 32-bit Micro Channel. Other vendors coun-tered with a 32-bit Extended ISA (theEISA). The PC/ISA/EISA buses are back-ward compatible: that is, expansion cardsdesigned for an older bus will normallywork in a newer bus slot. Thus, an 8-bitdisplay board from a PC bus works in a16-bit ISA slot or a 32-bit EISA slot, but a16-bit display board for an ISA bus doesnot work in an 8-bit PC slot.

button: A control component in a windowthat is activated by positioning the mousecursor over it and pressing the left mousebutton. A button may be one of severaltypes: push button, radio, toggle, check,cascade, or option.

B/W photo, B/W image, B/W display, orB&W: A black and white photograph orsome other monochrome image renderedin black, white, and shades of gray.

byte: A data element made up of 8 bits andhaving 256 possible values. In text-ori-ented processes, each byte represents onecharacter of text. In 8-bit raster pro-cesses, each byte represents one cell valueand may correspond to one pixel on theimage display. (See also: bit, exabyte,gigabyte, kilobyte, megabyte, pecabyte,terabyte, yottabyte, zettabyte.)

byte-oriented or 8-bit raster object: Araster in which each cell is representedby one byte (8 bits) and can thereforeassume 256 possible values.

— C —C and C++: High-level programming lan-

guages.

CAD:Computer Aided Design. CAD origi-nated on larger, dedicated workstationsand minicomputers and has now migratedto microcomputers. In its simplest sense,CAD is used for computerized drafting.Many CAD systems also provide moreadvanced features like solid modeling andsimulation.

cadastre: “An official register of the own-ership, extent, and value of real prop-erty in a given area, used as a basis oftaxation” (Random House).

CAD Editor: The process used in TNTmipsfor creating and editing CAD objects.Input can be from your computer’s mouseor from an X-Y digitizing tablet.

CAD object: A CAD object, in RVC format,like a vector object, is composed of co-ordinate data, but uses a different datastructure. A CAD object has a free-formtopology, so it may be useful for applica-tions that do not require an exact de-scription of the relationships between theelements in the object. CAD object to-pology does not reconcile things like lineintersections, polygon overlap, and poly-gon islands.

A CAD object also allows for descrip-


tions of geometric shapes. For example,in a vector object, a circle is always storedas a polygon, and at a high enough mag-nification, the discrete point and line el-ements become visible. By contrast, aCAD object stores a circle by its centerpoint and radius. Thus, at any magnifi-cation, it looks circular.

Since they have reduced topological con-straints, CAD objects generally requireless storage than their vector object coun-terparts. [See also: element (CAD).]

calibrate or cell size calibration: To es-tablish scale or cell size (for a raster) foran object in a project file. Once a raster,vector, or CAD object has been calibrated,accurate measurements can be determinedand displayed. (See also: georeference)

calibrated image map: See: image map.

cap style: The ends of dashed line segments,which are components of line patterns,are caps. You can assign a style to thiscap when you are creating or editing aline pattern in the Style Editor. The capcan be round or flat.

capacity: The number that can be accom-modated by a center in network analysis,such as the number of students a schoolcan accommodate, the quantity of per-ishable goods that can be delivered in oneday, the number of seats in a theater, orthe number of parking spaces at a shop-ping mall.

Cartesian coordinate system: A two-di-mensional, planar coordinate system inwhich x measures horizontal distance andy measures vertical distance. Each pointon the plane is defined by an x,y coordi-nate. Relative measures of distance, area,and direction are constant throughout theCartesian coordinate plane.

capture: To freeze and digitize a standardvideo input signal (such as VHS tape orbroadcast video). Some microcomputerdisplay boards offer video capture. (Seealso: frame-grabbing.)

cartography: The art or science of makingmaps.

CartoScript: A script written with the car-tographic scripting language in the TNTproducts, which provides a complete andflexible set of drawing functions that al-

low you to design custom map symbolsfor many applications.

cascade button: A type of button that dis-plays a cascading menu. A cascade buttonis typically a selection on a parentpulldown menu. It includes an arrowgraphic that points in the direction thecascading menu appears.

cascading menu: A submenu that opensfrom a selection on a parent pulldown orpopup menu that provides selections thatsupplement the parent selection.

catchment: (watershed analysis) The entirearea drained by a stream and all of itstributaries, with all runoff draining to thesame outlet. In nature the outlet may be alake, the ocean, or other water body. Inthe Watershed process, the outlet mayalso be the point where a particular flowpath intersects the spatial boundary ofthe elevation raster being analyzed. Syn-onym: watershed.

categorical data: Data in a raster object issaid to be categorical if it cannot be rep-resented by a continuous surface, sinceintermediate terms cannot be derived withmeaningful results. Example 1: soil typedata cannot be interpolated, since a soiltype 14 and a soil type 15 cannot sensi-bly be averaged to derive a soil type 14.5.Example 2: feature classification data can-not be interpolated, since a cell assignedmembership in the feature “corn” can-not sensibly be used in any process thataverages it with a cell assigned member-ship in the feature “wheat.”

Do not confuse the terms “categoricaldata” and “category”—they have differ-ent and distinct meanings.

category: (in Feature Mapping) A subdivi-sion within a region of interest (whichalso has a particular meaning in referenceto Feature Mapping) that lets you dividethe study site so that the measurementdata in the output text file will be orga-nized geographically. So, if you have de-fined a region of interest as the wetlandduck habitat along a river floodplain, youmight want to divide the wetlands intocategories: perhaps ownership areas (likerefuge lands, private ownership, and ease-ment areas). Then the text output filewould break down the wetland feature


measurements by ownership area. If youdo not define categories, TNTmips treatsthe entire region of interest as a singlecategory (and does not subdivide the fea-ture measurements in the output data).

Do not confuse the terms “categoricaldata” and “category”—they have differ-ent and distinct meanings.

CAT scan: A medical diagnostic image pro-duced by Computer Aided Tomography.

CCITT Comité ConsultatifInternationale de Télégraphique etTéléphonique (International Telegraphand Telephone Consultative Committee):A standards organization that has devel-oped a series of communications proto-cols for the facsimile transmission ofblack-and-white images over telephonelines and data networks. The CCITT ac-ronym in TNTmips represents a type oflossless raster compression that is usedfor 1-bit images.

CD-R: Compact Disk-Recordable. A 5" opti-cal disk that can be written to by a CDburner.

CD-ROM: Compact Disk, Read-OnlyMemory. A 5" optical disk containingprerecorded data sets.

CD-RW: Compact Disk-Rewritable. A 5"optical disk that can be written to by aCD burner in multiple sessions.

cell: One value in a raster that correspondsto a specific area on the ground. A rastercell may contain a value that describesthe elevation above sea level at one posi-tion in a survey site or the intensity ofred radiation for a pixel in a video image.For convenience, a raster cell is usuallythought of as square or rectangular, al-though many image collection devices ac-tually measure circular or elliptical areas.If a raster object is created from a screenimage, each cell value represents one pixel.

cell size: The dimensions of the area on theground to which a raster cell value ap-plies. A cell size of 30 meters signifiesthat the value in each cell of the rasterobject applies to a 30 x 30 meter area inthe study site.

cell size calibration: The transfer of cellsize information to a raster.

center: A point within a network to which

materials or people are brought or fromwhich materials or services are distrib-uted.

central meridian: The north-south me-ridian of a map projection around whichthe map is centered.

centroid: “The point that may be consid-ered as the center of a one- or two-di-mensional figure, the sum of the displace-ments of all points in the figure fromsuch a point being zero” (RandomHouse).

CGA: Color Graphics Adapter. An earlymicrocomputer graphics subsystem de-veloped for the IBM PC. The CGA washampered by low resolution and limitedcolor selection. It has been supercededby EGA, VGA, SVGA, 8514/A, and XGA.(See also: EGA, VGA)

CGI: Common Gateway Interface.

CGM: Computer Graphics Metafile is agraphic image exchange format.

change image: An image produced usingraster algebra that shows change overtime between coregistered images.

character: An element used for the graphicrepresentation of data (such as a letter,numeral, or symbol) or control of data(such as a tab, space, return, or enter).Each element has a corresponding char-acter code in the Unicode table.

check button: A square button in a pop-inwindow that presents one selection in agroup of on/off options. When a checkbutton is “on,” it appears “pushed in”.Clicking on one check button does noteffect any other check buttons in thegroup. (See also: radio button.)

chip: Commonly, any integrated circuit logiccomponent of a computer.

CIR image: Color-infrared image. Color-infrared images may be collected by anelectronic scanner or a camera that usesspecial film with sensitivity from greenthrough infrared. The photographic in-frared radiation just beyond the range ofhuman vision is then displayed as red.Normal red from the scene becomesgreen, and green becomes blue. Normalblue in the scene is filtered out and notrecorded. CIR images are used to show


the vigor of plant life. Healthy vegeta-tion appears red, while distressed or dam-aged vegetation may look pink, tan, oryellow. (See also: color-infrared image)

class: (raster) A set of all image features ofthe same type. As part of the interpre-tive process, the user names a class toidentify the type of material it contains,like “corn,” “bare soil,” “wetland,” or“urban.” In a set of coregistered rasterobjects, a grouping of cells with similarsets of values. A class normally corre-sponds to a specific land cover type witha restricted set of biophysical proper-ties.

class center The set of raster values thatdefine the mean vector for the class infeature space.

classification: Grouping cells (often bycolor characteristics) from coregisteredrasters to map the location and type ofimage features (like type of crop, sur-face cover, and map line type).

class list: A subobject containing a list ofclasses associated with a vector or CADobject.

class numbers/renumbering (LAS):

client/server: A software system has a cli-ent/server architecture when there is acentral processor (server) that acceptsrequests from multiple user processes (cli-ents), such as TNTserver and TNTclient.

clip: Clipping limits the extents of a layer orgroup for the purpose of display. Clip-ping extents can match a reference ob-ject or use geographic coordinates.

clipping area: The regular or irregular areathat will be processed and is defined bydrawn polygons or a region.

clip art: Icons, symbols, and drawings dis-tributed in computer-readable format.Computer clip art was popularized by theApple Macintosh, which can use pub-lished clip art for electronic cutting andpasting into drawings or pages of text.TNTmips users can similarly create andshare a variety of original symbols, pat-terns, and line types.

clump: A set of contiguous line, node, andpolygon elements in a vector object.

clustering: A process in which multiple,

registered, overlapping, rasters are reducedto a single raster, which is referred to as acluster map. The rasters used in cluster-ing represent analytical data (such as im-ages and elevations). Different cluster-ing methods (such as K-means, Fuzzy C-means, and Isoclass) use varying logic toaccomplish this mapping and dimensionalreduction. In general, all of the methodsuse the concept of testing multiple valuesfor each cell against all other cell valuesto determine which subpopulation eachcell is most similar to and should begrouped with. All clustering methods firstmake a preliminary set of groups by test-ing all cells or a sample of them. Theythen proceed by various methods to testindividual cells and dynamically redefinethe clusters until every cell is satisfacto-rily assigned a cluster membership in asingle cluster, which is recorded at thatcell’s position in the cluster map. Themaximum number of clusters to form andthe number of refinement iterations isusually controlled during setup. (See also:labeling, unsupervised classification)

cluster labeling: Identifying and groupingthe clusters in the cluster map raster ob-ject that result from any kind of auto-mated image interpretation. The userchooses labels (names for types of fea-tures) based upon his or her knowledge ofthe areas or materials in the image. Usethe TNTmips Feature Mapping processto label (and possibly combine) the clus-ters.

cluster map: The output raster created byclustering or by unsupervised classifica-tion. The clusters are usually identifiedor labeled as some useful type of material(for example, an agricultural crop, a bodytissue type, or a soil type). It is impor-tant to note that this raster does not con-tain values that can be subjected to fur-ther mathematical analysis because theclusters and their reidentification as ma-terial or area types do not represent datavalues that are mathematically continu-ous. For example, cells in a cluster arbi-trarily assigned the value of 4 by the clus-tering process does not necessarily repre-sent twice as much of something as a cellassigned to a cluster that was given a valueof 2.


CMY or Cyan-Magenta-Yellow: The stan-dard set of subtractive, processing colorsused in printing. Color printing devicesuse discrete dots of cyan, magenta andyellow to present the appearance of afull-color image to the human eye. Thecombination of cyan, magenta and yel-low produces black. However, someprinters include black ink along with theabove three colors, which is properlycalled CMYK.

CMYK or Cyan-Magenta-Yellow-Black:See CMY or Cyan-Magenta-Yellow.

CMYKcm: Used with six-color printers.Cyan-Magenta-Yellow-Black-Light Cyan-Light Magenta.

codec: Short for compressor-decompressor.The term applies to any technology usedfor compressing and decompressing data.QuickTime Player and Windows MediaPlayer use codec technologies.

Codec can also stand for coder-decoder.In this context it refers to an analog todigital and digital to analog converter thatconverts real-world signals to digital formand back again. Codecs can be imple-mented in software, hardware, or a com-bination of both.

coextensive: Covering the same ground areaexactly. If two raster objects are bothcoregistered and coextensive, there is a1:1 cell correspondence for ground areacoverage in each cell of the rasters.

COGO: The Coordinate Geometry (COGO)process includes COGO commands thatwhen executed accomplish meaningfulfunctions for professional surveying andcivil engineering applications. COGO bydefinition is a command structured prob-lem oriented language and computer pro-gram for the solution of geometric prob-lems. COGO tools are useful for creatingor editing vector or CAD objects with landsurveying, global positioning system, andother precision data. The COGO ap-proach has been used by surveying andcivil engineers since approximately theearly 1960’s. COGO relates to the LOGOlanguage used in early computing and per-mits the creation of precise control anddescriptive data entry into new or exist-ing objects tied to the ground surface, pro-jection, and datum. COGO points and the

objects defined by those points, can bedetermined in 3D space within the inte-rior of an object (for example rooms andhallways in a building; adits, shafts, andvarious tunnels in an underground mine;locations in a timber stand; or areas in ahydro-geologic environment) and can beused to define interior surfaces in vectorapplications and solid objects in vectorand CAD applications.

color balancing: Adjusting the intensitiesand distribution of red, green, and blue tocreate an image with a particular colorappearance for display or printing.

color compression: Removing duplicate(in some cases near-duplicate) colorsfrom a color map to make room for newcolors.

color depth or pixel depth: The numberof data bits each pixel represents. In 8-bit contexts, the pixel depth is 8, andeach display pixel can be one of 256possible colors or shades of gray. With a24-bit raster (or with three coregistered8-bit rasters) the pixel depth is 24, and16,777,216 colors are possible.

color-infrared (CIR): Color-infrared im-ages may be collected by an electronicscanner or a camera that uses special film.Infrared film records the photographicinfrared radiation just beyond the rangeof human vision as red. Normal red fromthe scene becomes green, and green be-comes blue. Normal blue in the scene isusually filtered out and not recorded.

Any physical or biological damage togrowing plants which begins to cause adeterioration in their vigor (their waterand/or chlorophyll content) causes arapid decrease in their reflectance ofphoto-infrared radiation, and increasesin their red reflectance. CIR photographsshow these changes much sooner andmore dramatically than normal photo-graphs or human eyesight. Healthy,green vegetation appears in bright red,while damaged, diseased, or dying veg-etation appears in shades of pink, tan,and yellow.

This knowledge was first used during theSecond World War when color-infraredfilm was called camouflage detection film.It provided pre-visual detection of the


changes in vegetation cut or damaged bymilitary activity and could very easilyseparate color-camouflage materials (likeolive drab canvas) from live foliage.

color map or color table: A color map isthe table, or map, used by a computersystem to assign display colors to digitalvalues. A color map for an 8-bit rasterobject can contain a total of 256 colors.A gray scale image may have a color mapwith 256 shades of gray, ranging fromblack (0) to white (255). The first 64places in a color map are normally as-signed to the “standard 64” annotationcolors. Additionally, certain processesmay use 16 values for standard shades ofgray. The remaining 176 or 192 colorsare then available for the image colorsused in the display. Some types of colormaps that you will encounter in TNT-mips are optimized color maps and com-posite color maps.

color palette editor: A TNTmips windowwhich shows a table of the current dis-play colors. With 8-bit data and devices,this palette includes 256 colors in 8 rowsand 32 columns of color cells.

color separation: Manipulating a full-colorimage in order to extract features of onecolor or range of colors. The color sepa-ration process can be used to create abinary raster object from a compositecolor raster object (or a set of three RGBraster objects) to lift out blue line im-ages, for example, leaving behind back-ground colors and lines images of othercolors. Printers use related color separa-tion techniques to prepare process colorseparates from full-color originals.

column: A vertical list of data values ordisplay cells in a raster object or display.

command: A specific instruction to a com-puter program entered by the user to per-form a desired action.

command prompt: Formerly called theDOS prompt on PCs, it is a path thatincludes a drive letter followed by a : (co-lon) that ends in a > (greater than sym-bol) found in a command shell with eachdirectory level separated by a slash.

component: Any single element in a win-dow, including buttons, fields, scroll bars,sashes, panels, menus, panes, frames, dia-

log boxes, or separators.

compose sequence: A sequence of two ormore keystrokes used to create a singlecharacter, as in the case of European lan-guages that have characters with variousdiacritical marks.

composite color raster object: A rasterobject in which each cell contains a datavalue representing one of the colors intowhich all available color data for that cellhas been compressed. For 8-bit rasterobjects, there are 256 possible colors foreach cell; for 16-bit raster objects thereare 32,768. Composite color rasters areusually compressed from a red/green/blueraster set that retains a wider range ofcolor information. The composite ras-ter still produces near photographic qual-ity color displays.

composite color video: The standard colorvideo output of a VCR or video camerathat adheres to the NTSC video standard.All the color information is contained inone signal (instead of in the three RGBcolor signals).

computed field: A field in a database tablewith a value calculated from the values ofother fields in the same or different tablesof a single database. You define the ex-pression used to generate the values for acomputed field using the same languageand syntax employed for database que-ries. The appropriate record values foruse in a computed field are determinedthrough primary and foreign key relation-ships or by element attachment.

conflation: Determining a single resultantline from coincident or nearly coincidentlines while merging or editing vector ob-jects.

conic projections: This group includes pro-jections that are constructed by placing acone tangent to the globe along a stan-dard parallel in the mid latitudes, or in thecase of a polyconic projection, placing acone secant to two (or more) standardparallels. Conic projections are com-monly used to depict hemispheres orsmaller portions of the earth’s surface.

context: A file that describes how to recreatea web map that may be made up of manydifferent layers from many different WebMap Services (WMSs).


continuous data: Data in a raster object issaid to be continuous if it can be repre-sented by a three-dimensional surface suchthat intermediate values can always bederived with meaningful results. Example:an elevation raster has continuous databecause an elevation of 400 and an eleva-tion of 500 can fairly be averaged to as-sign an intermediate elevation of 450.

continuum: Continuous extents with no ob-vious division into parts.

contour map: A topographic map that usescontour lines to portray relief. Contourlines join points of equal elevation.

contours: Lines on a contour map or otherisomorphic map that identify levels of aparameter at specified, discrete intervals.

contrast: The difference between bright anddark values in the display or printout of acontinuous tone (usually grayscale) im-age. The stronger the contrast, the moredifference between the brightest and dark-est values. Most images benefit from aprocess of contrast enhancement, whichartificially increases the contrast.

TNTmips provides different methods ofdistributing intermediate display or printvalues. The Linear contrast model as-signs straight-line increments of inten-sity. Many images look better when theyare produced with the Normalized con-trast model, which assigns intensity in-crements according to a normal distribu-tion curve.

contrast table: A contrast table assigns dis-play intensity values to raster object cellvalues using a specified translationmethod, such as linear or normalizedtranslation. The type of translation cho-sen and the limits defined will change thedisplay values but, in general, the result isto increase the apparent differences be-tween the majority of cell values, whichusually fall within a narrow range.

control panel or panel: An area of a win-dow that holds related buttons, sliders,fields, and other components used to gov-ern the behavior of a process.

control point: Points, elevations, and/or cellswhich are used to establish map coordi-nate control for ungeoreferenced objectsor objects that are to be used in a process

such as Stereo Modeling. In the manualmosaic process, a control point is a fea-ture in a piece of the mosaic (such as aroad intersection) for which the map co-ordinates are known. In the raster-to-vector calibration process, a controlpoint is a feature that is co-located be-tween the ungeoreferenced raster object,and the georeferenced vector object over-lay. A control point may be somethinglike a bend in a river or a road intersec-tion that shows on both a raster objectand an overlying vector object. Tyingcontrol points together lets TNTmipsadjust scale, orientation and geometricdistortion between rasters and vectors.

TNTmips’ georeferencing and registra-tion processes rely on control points in-troduced and identified on the displaywith the mouse. (See also: tie points)

control point list: One type of map regis-tration subobject (Regist) that containsa paired list of map coordinates and cellcoordinates. TNTmips uses the controlpoint information to derive map cali-bration for the entire object. (See also:linear transform)

controls window: The TNTmips displayand edit processes always include at leasttwo windows: the controls window andone or more view windows. A single con-trols window can govern multiple viewwindows.

convolution: Mathematically determiningthe data value for a new cell in an m x nneighborhood of cells. Raster filtering,resampling, and other raster processesuse convolution. Convolution processesshould never be applied to raster objectsthat contain categorical data. Convolu-tion is only appropriate for continuousdata.

co-occurrence raster: A raster created inthe Color Binarization process. The cellvalues in the co-occurrence raster are thefrequencies of occurrence of the samecell value in adjacent cells in the inputraster object. The Color Binarizationprocess analyzes groups of eight neigh-boring cells in the input raster object todetermine the occurrence of the samecell value within the group of cells.


coordinate: A set of numbers that designateposition in a given reference system, suchas X-Y in a 2D coordinate system and X-Y-Z in a 3D system.

coordinate system: A reference system fordefining precise locations on the earth’ssurface. Coordinate systems may be in-dependent of or tied to a particular mapprojection.

coprocessor: Older microcomputers usedfor heavy computational tasks had a sec-ond microprocessor, called a mathcoprocessor. To speed things up, the mainCPU assigned its tedious arithmetic tothis helpful specialist in much the sameway that modern accountants use calcu-lators for the computations their grand-fathers did by hand. In the Intel CPUseries, the main processor’s chip numberended with the digit 6 and thecoprocessor’s chip number is the sameexcept for the final digit 7: 80286 /80287; 80386 / 80387. Since the 80486,Intel has included the math coprocessorin the basic design. (Thus there was no80487).

coregistration: The condition in which as-sociated raster and/or vector objects over-lay each other with correct orientationand geometry so that corresponding in-ternal features align.

correlation: The degree of relatedness be-tween two objects; more specifically, thedegree to which one value in a set ofvalues can be used to predict the corre-sponding value in another set of values.

correlation points: (also called tie points).A pair of points collocated on a com-mon feature, such as a road intersection,in a pair of images. A set of correlationpoints defines the mutual spatial rela-tionship of a pair of overlapping imageswithout regard for their real position in amap coordinate system.

cost raster: A cost raster is a raster objectwith cell values that represent a priceper distance unit; for example, monetaryexpenditure per meter, fuel usage permile, traversal time per mile, and so forth.

coverage file: See: pcARC/INFO coveragefile.

CPU: Central Processing Unit. The main

computing engine of a computer.

CRS: Coordinate Reference System.

CRT: Cathode ray tube.

cross validation: An option in the Krigingmethod of Surface Fitting in the SurfaceModeling process. This option is a pre-processing function that calculates themean error and standard deviation for es-timated control points compared to theactual control points.

cubic convolution or cubic interpolation:A computationally intense interpolationmethod used in raster resampling. Thismethod determines a new cell value toproduce a smoother result by fitting acubic polynomial surface to a 4 x 4 neigh-borhood of cells. Bilinear interpolationnormally produces results which are al-most as good. Cubic convolution shouldnot be applied where the mean data valuefor a group of cells is undefined as in cat-egorical data (like an 8-bit color rasterobject, a classification map, or any rasterobject containing similar category-typedata).

cursor: See: mouse cursor, text cursor.

cursor hot spot: The pixel location on acursor shape at which the cursor activitytakes place. For example, the hot spoton an arrow cursor is at the point of thearrow, while the hot spot for a cross-haircursor is at the intersection of thecrosshairs.

cylindrical projections: This group of pro-jections includes all projections con-structed by placing a cylinder tangent tothe globe along a standard parallel—usu-ally the equator, or secant to the samestandard parallels in opposite hemispheres,respectively.

Cyrillic: An alphabet widely applied to theSlavic languages, as in the case of thethirty-three-letter Russian alphabet. Sincethe 1930’s it has been used for most ofthe languages of the former Soviet Union.(Attributed to Saint Cyril, a ninth-cen-tury Christian apostle of the Slavs.)


— D —dangling line: A dangling line element in-

tersects another line element on only oneend. The unattached end terminates in anode element that is not shared by an-other line element. Dangling lines maybe either overshoots or undershoots.Dangling lines can be avoided by usingthe snap options when editing.

database form: A database form allows youto reorganize the information in a tablefor display in single record view. Thisreorganization may include changing theorder and placement of fields and / or dis-playing only selected fields from an ex-isting database table. You can also modifyfield titles to include spaces, which arenot allowed in actual field names, to ex-ceed the 15 character maximum, or youcan change the name entirely if the origi-nal seems too cryptic for the intendedaudience. You can also add text that isnot associated with a particular field toprovide logical groupings for the infor-mation presented in the form. A databaseform cannot exist without an accompa-nying database table. Editing in the de-fault table layout or in any of the formscreated as an alternate means of viewingthe same information alters the single setof values used in all cases. Database formsare stored as subobjects of the database.

database object or dBASE object: A data-base is a collection of information re-lated by some unifying theme, such as de-mographics, epidemiology, or geographiclocation. There are a number of populardatabase programs, such as dBASE IV, thatassist in the retrieval and management ofsuch information in electronic form. TheTNT products also handle databases anduse specific terminology for the compo-nents that comprise a database. A data-base in the TNT products can be a mainlevel object or a subobject of a raster, vec-tor, CAD, or TIN object. The object gen-erally defines the “unifying theme” (forexample, the soil type polygons for theCrow Butte area). A database is organizedinto tables, which contain records that

store attribute values for an individualexample in one or more fields. (See also:external database, field, foreign key, in-ternal database, primary key, record,table.)

database query: The database tables at-tached to vector/CAD objects can be que-ried to reveal those elements that meetthe criteria specified in the query anddrawing styles can be assigned in accor-dance with query results. Database querycan be used to select vector/CAD ele-ments for display and assign their draw-ing styles.

data mask: A processing barrier that onlyallows data values in a chosen range topass. You might choose a data mask toblock all values outside a selected colorrange, eliminating all image features ex-cept those of the color you want to usein a process. You can also use a mask toselect a processing area from a largerscene. The mask blocks off the partsthat you want to exclude from the cur-rent analysis.

DataTip: A DataTip contains a raster cellvalue or element information for vec-tor, CAD, shape, or TIN objects. For allobjects except raster objects, you can des-ignate the database table and field for useas a DataTip. Place the cursor over thecell or element for which you want tosee a DataTip and wait briefly. DataTipsoperate in a manner similar to ToolTips.In TNTmips, a virtual field can be usedto produce a multiline DataTip. SuchDataTips present information from mul-tiple fields in one or more database tables.

datum: A mathematical description of asmooth surface that closely fits the meansea-level surface for an area of interest,which provides an imaginary, perfectlyflat horizontal surface for use as a mapbase with x,y coordinate measurements.A datum is derived from a chosen ellip-soid, and provides the surface to which acartographer refers ground control mea-surements. Maps of large extent mustuse consistent parameters for ellipsoidand datum to insure consistency betweenthe map projection and ground control.(Map Projections Used by the U. S. Geo-logical Survey, Geological Survey Bulle-tin 1532, Second Edition, U. S. Govern-


ment Printing Office, Washington, D.C.,1982, pp. 13-15). (See also: ellipsoid.)

daughter object: A completely indepen-dent project file object that may betreated by TNTmips as subordinately re-lated to some other object. For example,objects attached by HyperIndex® tosome other object are called its daugh-ters and the object used for the primaryindex layer is called the parent. (Seealso: HyperIndex, index area, parent ob-ject, stack)

decibel rasters: Radar images in which theraster cell values are presented as log scalevalues based on the power of 2. Userscan choose to generate decibel raster ob-jects in addition to raster objects withlinear cell values when they import JPLAIRSAR and TOPSAR radar formats.

decision rule: The criterion used to assigncells to a prototype feature in TNTmipsfeature mapping. Cells in the image aretested against the decision rule, and thosethat match are highlighted as prototypes.You select the desired decision rule whensetting up the raster objects to be ana-lyzed by feature mapping. A simple deci-sion rule would be to compare the threecolor values of each cell on the displayto three color values known to occur inthe target feature.

DCW: Digital Chart of the World was thefirst digital 1:1,000,000 map of the worldin VPF format. This data can be down-loaded from the NGA website. This origi-nal product has been replaced by themore detailed VMap0 and VMap1 datasets, which are also available for down-load from NGA.

defaults: The start-up settings for a systemor an individual process. In TNTmipsthe defaults are usually automatically setto be the most probable value desired ifthe process is to be repeated either im-mediately or at some indefinite futuredate. Many TNTmips defaults are set tothe last value, raster object, position, orother parameter used. Some defaults arealways reset to a selected condition, re-gardless of the last choice, in order toprevent inadvertent destruction of valu-able results and data sets. For example,the location of a new output raster ob-

ject will not usually default to an existingobject to avoid accidentally overwritingit. Well thought out defaults are one ofthe simplest and most easily incorporatedforms of artificial intelligence that canexist in a system.

degree or °: A unit of measurement equal to1/360 of a circle. A degree of latitude onthe earth’s surface is about 69 miles. Adegree of longitude is about 69 miles atthe equator and undefined at the poles,but any point on the surface rotatesthrough a degree of longitude in about 4minutes of time. (See also: arcsecond,minute.)

Delaunay criterion: A conditionthat must be met when a TNTmips TINobject is computed. The technique usedto generate the TIN object, known asDelaunay triangulation, produces a set oftriangles that are as equi-angular as pos-sible. All circumcircles of Delaunay tri-angles contain no points other than thethree that define the triangle and its cir-cumference. Satisfying the Delaunay cri-terion ensures that any point on the sur-face is as close as possible to one of thenodes, the number of long skinny trianglesis minimized, each sample point is con-nected with two nearest neighbors to forma triangle, the triangulation solution isunique and independent of the order inwhich the points are processed, and thesolution produced allows easy generationof Voronoi diagrams (Thiessen polygons)for the same set of input points. Voronoidiagrams are widely used in spatial analy-sis.

DEM: Digital Elevation Model. (Also DTM,“Digital Terrain Model”). A computer-ized representation of an elevation sur-face. Specifically, a raster in which thevalue in each cell represents the surfaceelevation at that location in the scene.DEMs are USGS geographic elevation datadistributed in raster form on open reelmagnetic tapes. There are 2 basic types:1) The DMA type created by the DefenseMapping Agency in both a fixed cell sizeand a 3 x 3 arcsecond cell size distributedin 1 x 1 degree files. 2) A newer formatfor those 7.5' USGS quadrangles that havebeen processed into 1 x 1 arcsecond el-


evation cells.

demand: The number of something that usesa center in network analysis; for example,the number of students living along a roadplaces a demand on a school (a center).Demand values are necessary before ca-pacity limits can be meaningful.

dendrogram: A tree diagram whose branchesdepict a hierarchical classification struc-ture, showing the degree of relatedness ofdifferent classes.

densification: Densification of vector linesadds vertices to a line to enforce a par-ticular shape generated by splining. TINdensification is the process of addingnodes to a TIN object based on some cri-terion, such as highest deviation from aplanar surface in an underlying DEM orcorrelation between a stereo pair ofDEMs. (See also: TIN densification.)

depression: (watershed analysis) A depres-sion exists when the lowest elevation valuewithin the watershed is lower than thelowest value of the cells that form thewatershed boundary. Drainage is inwardfrom the inside perimeter of the depres-sion toward the lowest point.

depressionless raster: An elevation rastercreated from the original elevation rasterwith all depressions filled. Such depres-sions are filled by assigning increased el-evation values until a flow direction canbe established without going uphill. Thedepressionless raster is attained when thenumber of depressions is reduced to zero.

destripe: Procedure that removes system-atic striping within an image. This strip-ing typically occurs in an image gener-ated by a multispectral scanner thatsweeps multiple scan lines simultaneously.

developable surface: A geometric form ca-pable of being flattened without stretch-ing or tearing, such as cylinder or a cone(both of which can be cut and laid outflat), and a plane (which is already a flatsurface).

device independent: Not constrained byidiosyncrasies of hardware environment.All processes in TNTmips function inde-pendently of the physical input, output,and display devices. Device independentsoftware is also designed so that all of its

procedures look and work the same wayacross a variety of hardware configura-tions.

DGIS: Direct Graphics Interface Standard.

diacritic: An accent mark added to a char-acter to distinguish it in pronunciationor meaning from other uses of the samecharacter. Common diacritics, for ex-ample, distinguish several versions of theLatin character “a:” á, à, â, ä, ã, and å.

dialog box: A type of subwindow that opensto display a message, warning, process-ing message or application componentsthat require the user’s input. The usermust typically make some kind of deci-sion and exit the dialog box before con-tinuing with the process by pressing abutton such as OK, Cancel, or Skip.

diapir: An upfolded geologic structure, suchas an anticline, in which mobile, plasticcore material has broken through orpierced the more brittle overlying rock.

digital: Information stored and processedwith numerical digits, often in base 2.Digital information processing is con-strained by the finite set of numbers asystem uses, such that every data value isforced into its nearest representation.For example, a digital clock may onlyshow hours, minutes and seconds, but notfractions of a second. At some point,every digital system faces the same kindof limit in accuracy. On the other hand,digital information is easy to copy, store,manipulate and reproduce dependably.(See also: analog.)

Digital Elevation Model: See DEM.

Digital Terrain Model: See DEM.

digitize: Convert analog data into a digitalform; also, more specifically, use an X-Ydigitizing tablet to convert data to digi-tal form.

digitizer: A device that converts an analogsignal or representation to a digital one.(See also: scanner, video digitizing board,X-Y digitizer.)

digraphia: Use of two different scripts forthe same language, such as Latin andCyrillic for Serbo-Croatian, Devanagariand Arabic for Hindi-Urdu, and Pinyinand characters for Chinese.


dimensionality: The number ofcoregistered images in a project file forone site. An image contained in onecolor composite raster has a dimension-ality of one. An image contained in athree-raster RGB set has a dimensional-ity of three. A Landsat TM image mapfor a single date will have a dimensional-ity of up to seven.

If elevation rasters, panchromatic ras-ters, and multi-date airphotos are addedto the project file, the user will likelywant to reduce the dimensionality of theimage to simplify analysis and manipu-lation. (See also: dimensional reduction)

dimensional reduction: Reducing thenumber of coregistered rasters in a projectfile to speed up their analysis. TNT-mips’ dimensional reduction techniquesinclude principal components and Kauth’sTasseled Cap.

dimmed selection: A menu selection thatis not currently available as indicated byits grayed-out appearance.

directly attached: The relationship of anattribute table to elements when the tableattachment type is anything other thanRelated Only. Directly attached tabletypes include implied one-to-one (notavailable for CAD), one record per ele-ment, one to one, and no restriction.

directly linked: Directly linked files arefiles that can be read directly by the TNTproducts without using the import pro-cess to establish the link. Examples offile types supported for direct linking, ordirect use, are JPEG2000, MrSID,shapefiles, and DWG. For more infor-mation see the Quick Guide entitled Di-rect Use of Popular Geodata Formats.

directory or sub-directory: In DOS,Linux, and UNIX, a directory is a logi-cal, user-defined division of a storagedevice. For example, a user may divide ahard disk into several directories, witheach directory used to store files thatpertain to a certain task. One directorymay contain programs and documentsfor word processing, another for spread-sheet analysis, and another for databasemanipulation. Newer operating systemsuse the word folder synonomously with

directory.

discrete values: Cell values of rasters thatrepresent discrete data, such as categori-cal data, for which interpolated valueshave no meaning.

disk drive: A mechanical component of acomputer that allows data to be read fromor written to a spinning magnetic or op-tical disk.

displacement: The difference between theapparent x,y position of a feature in araw photo and the feature’s true position.Displacement is caused by camera char-acteristics, tilt, nearness to the targetscene, and variations in the elevation ofthe target terrain.

display: Display is used loosely to mean amonitor or what is drawn on it, but in thecontext of the TNT Display process, adisplay is a layout or group that is inde-pendent of other layouts or groups in theprocess. A display consists of a list oflayers in the Display Manager window andone or more View windows that show theselected layers.

display board or display card: An elec-tronic circuit board installed in a micro-computer that translates the computer’sdisplay data into signals for the monitor.

display group: A standalone grouping of lay-ers for the purpose of display (may alsobe a single layer). Groups can be com-bined in display and page layouts.

display histogram: A graph showing thenumber of times a data value occurs in araster display plotted against the range ofpossible values. For any RGB color theuser selects, the TNTmips display histo-gram shows how may cells there are inthe display for each intensity level of thatcolor.

display layout: One or more groups arrangedspecifically for onscreen purposes. Canbe converted to a page, or hardcopy, lay-out for printing.

Display Manager: The window in the Dis-play process that lists all the layers in allthe open displays. It provides the meansto open new or existing groups and lay-outs and to manage their contents.

display monitor or display screen: (his-torical term) One of the two screens in


the old DOS MIPS system (v3.3 and ear-lier). The display monitor showed theimage and worked with the mouse. Theother screen was the text monitor, whichworked with the keyboard and displayedmenus and system information.

dissolve: The removal of boundaries betweenpolygons that have one or more speci-fied attribute values in common.

distance raster: An output raster created bycertain classification methods whichrecords the Euclidean distance betweeneach cell and its assigned class center. Dis-tances are represented as 32-bit floatingpoint numbers. High distance values mayidentify cells which were not adequatelyclassified using the chosen method andinput parameters.

dither pattern or dithering: An image pro-cessing technique that creates the visualillusion of continuous tones when an im-age is printed. The illusion of shading isobtained by the calculated placement ofpicture elements that usually can not beresolved by the human eye. The calcu-lated placement of the picture elementsis called the dither pattern and createsmore colors and shades of color thanwould be printed otherwise on printerswith fixed intensity, fixed size printels.

dithered raster: A printer-ready 4-bit ras-ter object in which each cell correspondsto one dot (printel) on the hardcopy out-put from the printer.

DLG: Digital Line Graph. A USGS map for-mat usually used to distribute topographicmaps in vector form.

DMA: 1) Defense Mapping Agency of theUS Department of Defense. 2) DirectMemory Access.

double precision: A high level of accuracybased on the possible number of signifi-cant digits that can be stored for eachcoordinate or raster cell value.

DOS:Disk Operating System. DOS for per-sonal computers was developed and mar-keted by IBM and Microsoft from 1981to 1994. It provided management utili-ties for the files and other resources ofthe microcomputer. A DOS, or command,shell can still be accessed from MicrosoftWindows.

dpi: Dots Per Inch. A measure of scanner,screen, and printing resolution. The moredots per inch, the more detail a devicecan process for a given area of page ordisplay. On the other hand, the moredots per inch, the higher the demands onmachine storage and processing (files getlarge and processing slows down).

drag: To press and hold a mouse button whilemoving the mouse.

drag bar: A window’s title bar.

drape object: An object that takes its three-dimensional shape from a surface objectthat is lower in the layer list. Any objecttype that is usable in TNTmips can beused as a drape object.

drawing order: The order in which layersare drawn during display. The object thatis first in the drawing order will appear tobe on the bottom when all layers are dis-played. The order of objects in the layerlist reflects the displayed appearance fora group with the background always atthe bottom of the list.

drawing style: The style used to render ascreen or hardcopy representation of avector or CAD element. The drawingstyle for point features includes size andwhether unfilled, filled, or representedby a symbol. The drawing style for lineelements includes line width and whetherdrawn in solid color or using a line pat-tern. The drawing style for polygon ele-ments includes the border color andwhether or not a polygon is filled. Yourchoice of single color filling or use of atransparent fill pattern and whether todraw the border if filled are also part ofthe drawing style.

driver: A set of computer commands thatcontrol some input or output process fora particular type of hardware. Driverstranslate general program features intothe specific communication protocol re-quired by a particular device, such as aparticular printer.

dropout: A missing piece of an image, ormore generally, of a data stream. Drop-outs can be caused by the improper useor function of a hardware device, by sig-nal interference or disruption, or by otherproblems. A dropout in text transmis-


sion causes missing letters or words. Adropout in scanning can cause gaps inthe image of a line. Scanning a fine lineat too low a resolution or with too low abinary threshold is likely to cause drop-outs in the resulting raster image of theline.

DTM: Digital Terrain Model. Elevation datain a 3 x 3 arcsecond grid form or a simi-lar rectilinear form created by the De-fense Mapping Agency.

DVD: Digital Versatile Disc. A 5" opticaldisc for video or data with greater stor-age capacity than a CD-ROM (currently4.7 Gb).

DXF: Data Exchange Format for storing vec-tor or CAD data in ASCII or binary files,which can be used to interchangeAutoCAD files with other CAD software.

— E —easting: A rectangular (x,y) coordinate mea-

surement of distance east from a north-south reference line, usually a meridianused as the axis of origin within a mapzone or projection. False easting is anadjustment constant added to coordinatevalues to eliminate negative numbers.

edge conditions: In agricultural row cropimagery, the biomass values for cells inthe middle of a healthy row are high,while the thin plant fringes or bare soilbetween rows have low biomass values.Low biomass values along the edges ofhealthy rows are normal and are no causefor concern. But edges cannot be distin-guished by value alone from the low bio-mass values of regions of insect or dis-ease damage which must be identified andgiven special attention.

EGA: Enhanced Graphics Adapter. An earlygraphics subsystem capable of 64 colorsthat was widely used in DOS-based mi-crocomputers. The EGA was developedin 1984 to solve the poor resolution andlimited color selections of the CGA.

elgenvalues: Values used in theHyperspectral Analysis and PrincipalComponents processes. The dictionary

definition of eigenvalue is: a scalar forwhich there exists a non-zero vector suchthat the scalar times the vector equalsthe value of the vector under a given lin-ear transformation.

eigenvectors: Used in Principal Componentscalculations and the Hyperspectral Analy-sis process, eigenvectors have value anddirection. Eigenvectors are a mathemati-cal rather than statistical entity.

EISA: Extended Industry Standard Architec-ture. One of the standard bus architec-tures for microcomputers. (See also: bus.)

ELAS: A public domain, first-generation mini-and microcomputer image processing sys-tem developed by NASA at the StennisSpace Center in Slidell, LA.

elastic box: A rectangle displayed by TNT-mips which can be moved or resized withthe mouse. Elastic boxes are used to se-lect areas on the display monitor in pro-cesses like measuring and drawing.

elastic circle: A circle displayed by TNT-mips which can be moved or resized withthe mouse. Elastic circles are used to se-lect circular areas on the display monitorin processes like measuring and drawing.

elastic line: A line displayed by TNTmipswhich can be moved or resized with themouse. Elastic lines are used to draw seg-ments on the display monitor in processeslike measuring and drawing.

electromagnetic spectrum: “The entirespectrum, considered as a continuum, ofall kinds of electric, magnetic, and visibleradiation, from gamma rays having awavelength of 0.001 angstrom to longwaves having a wavelength of more than1 million km” (Random House). Re-mote sensing devices typically record elec-tromagnetic bands in the region of opti-cal light and may include the near infra-red. (See also: spectral band)

electronic atlas: A HyperIndex created frommaps, photos and airphotos, airvideo, anddatabase links. The electronic equivalentof a printed atlas.

element: (CAD) Any defined shape in a CADobject. These include arc, arc wedge, arcchord, box, circle, elliptical arc wedge,elliptical arc chord, ellipse, elliptical arc,line, point, polygon, and text elements.


A block inserted into another block alsoacts as an element at its insertion site.Unlike vector elements, individual CADelements retain their original shape re-gardless of what other elements are addedand where they are placed.

element: (vector) A vector object is made upof three different types of elements: 1)points, which are single coordinate pairs(or triplets) that define a point (such as awell); 2) lines, which are curvilinearstrings of coordinates which define acurved line (such as a stream) and whichhave nodes at the ends and intersectionsof lines; and, 3) polygons, which are col-lections of lines which inscribe an area(such as a lake).

ellipsoid: An ellipse rotated about its shorteraxis. In the context of map projections,an ellipsoid is a geometric reference sur-face that closely approximates the geoid.Since the geoid (that depicts the earth) isan irregular spheroid characterized bypolar flattening (or ellipticity), manymethods have been developed to describeits ellipsoidal deviations. Cartographershave a selection of ellipsoids from whichto choose; most of which have “best-fit”properties for certain portions of theglobe. In 1924, an International ellipsoidwas defined which described the earth el-lipsoid as a flattening of 1 part in 297.Historically, ellipsoids were derived fromcareful surface measurements. More re-cently, satellite data has been used to con-struct ellipsoid models that relate coordi-nate measurements to the earth’s centerof mass. A few common standards: GRS1980 (North America), WGS 72 (NASA/satellite), Australian (Australia),Krasovsky (Soviet Union), Clarke-1880(Africa), Clarke-1886 (North America,Philippines), Airy (Great Britain), Bessel(Central Europe, Chile, Indonesia),Everest (India, Burma, Pakistan, Afghan,Thailand, and other southern Asian coun-tries), and International (most other ar-eas).

EO cartridge: See: erasable optical cartridge.

EO drive: See: erasable optical drive.

EOS: The Earth Observation Satellite usedto study the earth as a system while track-ing long-term, global changes. EOS is a

NASA-sponsored mission.

epidemiology: The study of the variousfactors influencing the occurrence, dis-tribution, prevention, and control of dis-ease, injury, and other health relatedevents in a defined human population.

epipolar:A condition of geometric copla-narity established between a pair of ste-reo images to give them the same rela-tive orientation. Stereo images that haveepipolar orientation can be used to de-rive a network of correlation points inpreparation for DEM extraction.

EPPL7: Environmental Planning and Pro-gramming Language. A raster-based GISsystem developed and sold by the Stateof Minnesota.

EPS: Encapsulated PostScript.

EPSG: European Petroleum Survey Group.

equalized histogram: A histogram whosedistribution has been mathematically ad-justed so as to come as close as possibleto having an equal number of cells ofeach data value.

equator: The great circle that is equidistantfrom each of the earth’s poles and di-vides the earth into northern and south-ern hemispheres. Latitude is measuredwith reference to the equator.

erasable optical cartridge or EO car-tridge: A two-sided removable storageunit that typically holds between 300 and500 megabytes per side. Data on EOcartridges can be erased so the cartridgecan be updated or re-used.

erasable optical drive or EO drive: A 5 1/4" high capacity storage device that usesremovable double-sided cartridges whichtypically store between 300 and 500megabytes per side. EO drives are simi-lar to WORM drives, with the differencethat EO cartridges can be erased and re-used, while data on WORM disks is per-manent and cannot be erased. (See also:WORM drive.)

ERDAS: Earth Resources Data Analysis Sys-tem. A raster-oriented microcomputerimage processing and GIS system by LeicaGeosystems.

escape code: A code which controls theformat of text output. SML supports a


set of common escape codes: \t (tab), \b(backspace), \n (newline), \<carriage re-turn> (line continuation: the “stitch”character), and \\ (the ‘\’ character).

ESRI: Environmental Systems Research In-stitute headquartered in Redlands, CA.

Ethernet: Ethernet is a local area networkthat uses a bus topology for reliable highspeed communications in a limited geo-graphic area, such as an office of univer-sity complex.

euclidean distance: The shortest distancebetween two points in feature space, cal-culated using the Pythagorean theorem.

exabyte, Ebyte, or EB: A computer unit ofmeasurement for 260 (approximately)1,000,000,000,000,000,000 bytes,1,000,000,000,000,000 kilobytes,1,000,000,000,000 megabytes,1,000,000,000 gigabytes, 1,000,000terabytes, or 1000 petabytes. (See also:bit, byte, gigabyte, kilobyte, megabyte,petabyte, terabyte, yottabyte, zettabyte)

expansion slot: A socket for an optionalcircuit card on the main circuit board ofa microcomputer (the motherboard).

explicit destruction: When a user actionhas irreversible or negative conse-quences, the process requires the user totake explicit action and to confirm thatintent by responding to an appropriatewarning message, such as “Are you sureyou want to delete selected items?” be-fore destruction is performed.

exporting vector or raster objects: Ex-porting an object from a TNTmipsproject file converts it to a format rec-ognized by other image processing or GISsoftware. Color schemes; arc, node, andpolygon structure; geographic calibra-tion; and any other supporting data usedin the target format is included. Thecompleteness of the conversion is onlylimited by the extent to whichMicroImages can decode the format fromthe developer’s information or determineit from sample files.

expression: A line in a query or script thatcompares values. An expression evalu-ates to “true” (1) or “false” (0). Ex-ample: numlines < 3. It compares thenumlines variable for the current nodeelement with the number 3. The expres-

sion is true only if the value of numlinesis less than three. Also, an expressioncan evaluate to a number (for example:2*YIELD). If such an expression is usedwhere true and false values are needed, 0is treated as false, and anything else istreated as true.

extents: The geographic extent of data speci-fied by the minimum bounding rectangle.

external database file: A database file thathas been linked to a project file and ismaintained as a separate file. An exter-nal database file may still be processed byyour database programs. (See also: data-base object, internal database file.)

external program: A program that is notpart of TNTmips. It may be commer-cially produced or written by you.

external raster: A raster file that has onlybeen linked to a project file and is beingmaintained as a separate file. An exter-nal raster 1) is stored in a DOS file, 2)follows a very simple format, and 3) isnot stored internally in a project file. Toall TNTmips processes, this object stillappears to be a part of a project file. How-ever, external programs can modify it.

extrema points: The highest and lowestpoints and flat areas locally as indicatedby the elevation raster cell values. Ex-trema are change points determined bythe comparison of each cell to the eightadjacent cells. A cell whose eight bound-ary cells are all lower than the cell is de-fined as a single local maximum. A cellwhose eight boundary cells are all higherthan the cell is defined as a single localminimum. Two or more adjacent cellswith the same value whose boundary cellsare all lower are defined as contiguous lo-cal maxima. Two or more adjacent cellswith the same value whose boundary cellsare all higher are defined as contiguouslocal minima. Two or more adjacent cellswith the same value whose boundary cellsalso have the same value are defined as aflat area.


— F —false easting: An adjustment constant added

to easting coordinate values to eliminatenegative numbers. (See also: easting.)

false northing: An adjustment constantadded to northing coordinate values toeliminate negative numbers. (See also:northing.)

far range: The region farthest from theaircraft in an image created by a syntheticaperture radar (SAR) sensor.

FFT or Fast Fourier Transform: one of theprocedures in raster filters. See also: Fou-rier Transform.

feathering: One of the options availablefor handling cell values in the overlap-ping portions of the input objects in theMosaic process. Two types of Featheringmethods are available: Linear and Non-linear. Each type uses a weighted averageof corresponding input cells. Theweighted average varies with distancefrom the image boundaries. The weight-ing coefficients for each image are zeroat the boundary and increase inward to1.0 at the feathering distance from theedge (feathering distance is specified bythe user).

feature: An area in an image that you locateand map in the TNTmips feature map-ping process. A feature is a continuousarea (it may have holes in it) that doesnot touch any other area of the sametype. (When two features of the sametype touch, they immediately become asingle larger feature.) Features may rep-resent anything the user chooses to iso-late and identify, like ponds, lakes, agri-cultural fields, a biological entity in anNMR scan, or bones in a CAT scan.

feature class: The identity of a feature sup-plied by a TNTmips user. A class is a setof all features of the same material. Aclass is named to identify the kind ofmaterial it contains (for instance “corn”).

feature mapping: A TNTmips process forisolating, identifying, and typing areas inmultivariable images. TNTmips can do

most of the classification automaticallywhen working with high-quality materi-als like satellite multispectral images.With more input from the user, the pro-cess may also successfully map featuresin images created from 35mm slides ornoisy airvideo.

feature space: The theoretical n-dimen-sional space occupied by n input rasterobjects. Each raster object representsone dimension, and its cell values repre-sent positions along one of the orthogo-nal coordinate axes in feature space. Theset of raster values belonging to a celldefine a vector in feature space.

feature type: The identity of a feature sup-plied by a TNTmips user.

fiducial marks: (photogrammetry) In-dex marks, usually four, which are rigidlyconnected with the camera body andwhich form images on the film negativeand usually define the principal point ofthe photograph.

field: (database) One component in a data-base record. Fields report values (eitherqualitative or quantitative) for the indi-vidual represented by that record. Forexample, a database record in a table con-cerned with agricultural potential maycontain fields that provide qualitativeevaluations of a ground areas’ produc-tion potential for grain, legumes, or trees,while a database record in a table of poly-gon statistics may contain fields that re-port quantitative information such as thepolygon’s area, boundary length, and cen-troid coordinates. (See also: database ob-ject, record, table.)

field: (video) Background: The image yousee on a TV screen is composed of a setof about 480 horizontal lines. The linesare projected in two passes of the signalbeam. Each pass only projects everyother line of the image: the odd lines inone pass, and the even lines in the nextpass. One scan takes 1/60 of a second,so the whole picture (the frame) is re-freshed every 1/30th of a second.

A field contains every other line of thecomplete video image. The primary fieldcontains the odd lines; the secondary fieldcontains the even lines.


field: (window) An area of a window thatallows keyboard entry of text.

field of view: Area visible from a viewerslocation. In the Viewshed process youcan adjust the position of the viewpointlocation in relation to the vertical planeof the surface object.

figure-ground separation: Separation ofthe foreground (figure) from the back-ground (ground) in an image.

file: A stored collection of related material(programs and data) analogous to aphysical file folder that is used to store acollection of papers on a particular sub-ject.

file format: A particular, pre-described lay-out pattern for data in a computer file soit may be used or acted upon by a pro-gram. A TNT project file has a complexformat recognized only by the TNT fam-ily of products and by user programs de-signed and built with the TNTmips li-brary. Similarly, a commercial databasesystem uses only database files that fol-low its particular file format.

fill color: A solid color used to fill a closedshaped in a vector or CAD object or anarea defined by specified boundary col-ors in a raster object.

fill pattern: The drawing pattern for theinterior of a polygon for display or print-ing. TNTmips lets you create and assignfill patterns for raster (paint), vector,and CAD operations. A fill pattern canbe as simple as a solid color, or as de-tailed as a repeated image of a duck ortree. Soil types can be represented bytraditional color cross-hatching. Fillpatterns can be designed from the 64 stan-dard colors plus transparent (so the un-derlying image shows through).

film recorder: An output device that workslike a printer but produces slides or prints,usually on 35mm film.

filtering: Clarifying detail, sharpening con-trast, smoothing edges, and otherwise en-hancing image quality.

FIPS code: Federal Information ProcessingStandards code that identifies each state(2 digits) and county (3 digits). TIGERfiles are named by incorporating FIPScodes, e.g. TGR + 2-digit state FIPS code

+ 3-digit county FIPS code or TGR31109for Lancaster County, Nebraska.

flat: A raster cell that has the same cell valueas its eight neighbor cells. Calculated froman elevation raster object, a raster objectof flats provides a representation of lo-cations with poorly defined drainage.

flat tileset: A flat tileset is one that has nodirectory hierarchy. All the tiles areplaced in a single directory that mightcontain millions of tiles required to coverthe area of the source images or maps forall the zoom levels available. The nam-ing structure of each tile defines where itoccurs on the ground (i.e. its georeference)and its zoom level or scale.

Operating systems have limits on thenumber of files that can be in a directory.Vista and Windows 7 limit a FAT32 direc-tory to 65,536 files.

flight path: The path taken by aircraft, sat-ellite or other imaging sensor platform.The flight path controls the nadir as wellas the area imaged.

floppy disks, floppies, diskettes, or flex-ible disks: A thin, flexible magnetic diskfor computer program and data files.Floppies are inserted into a computer’sfloppy disk drive much like a cassette tapeis loaded into a tape player. Floppy diskscome in different sizes and capacities, andmust be used in the right kind of drive andcomputer. Floppies are slower and holdless data than a hard disk. (See also: harddisk, RAM disk.)

flow accumulation: In a raster-based analy-sis, the total number of cells, includingnon-neighboring cells, that drain into aselected cell.

flow direction: In a raster-based watershedanalysis, each cell is assumed to drain intoone of its eight neighbors (left, right, up,down, plus the four diagonals). The flowdirection of a cell is expressed in degrees:up=0, right=90, down=180, left=270; andthe diagonals: 45, 135, 225, 315.

flow path: The drainage path through a wa-tershed that begins at any selected point(called the flow path “seed”) and runs toone of the outlets of the study site.

flow path raster: A raster that indicates the


flow path from one or more seed pointsto one of the outlets of the study site.

flow path seed point: (watershed analysis)Any point selected to be the origin orhighest point in a flow, or drainage, path.

focal length: The distance from the lens atwhich parallel light rays are focused to apoint. Focal length is essentially a mea-sure of the “zoom” level of a camera lens.Longer focal lengths create a higher zoomlevel, capture a smaller area of the targetscene, and introduce smaller displacementerrors. 6-inch, 8.25-inch, and 12-inchfocal lengths are common for aerial pho-tography done by government surveyingauthorities in the United States. Focallength affects the geometry of the photoand must be provided as an input to com-putational orthoimage and DEM pro-cesses.

focus: Focus is generally thought of as a pho-tographic term, such that when things arein focus, they are not blurry. In software,however, many actions are defined bywhich window, field, or item has focus.Focus may be indicated by highlight ortext cursor position, and is generally ac-quired by a mouse click. Focus is some-times moved from one field to the nextusing the <tab> key.

folder: A folder contains a set of logicallyrelated objects in a Project File that havebeen organized so they can be accessedtogether. A folder is equivalent to a DOSdirectory. (See also: nested folders.)

font: A single set of glyphs (characters, sym-bols, numerals, and letters of both upperand lower case) of the same style (such asTimes, Helvetica, or Schoolbook). Fontscan be stored and manipulated in comput-ers as bitmapped or vector (outline, orstroke). Font sizes are specified in points.A 72-point font is one-inch high, fromthe highest ascender to the lowest de-scender in the set. A 12-point font is 1/6inch high. (See also: bitmapped font, out-line font, point size.)

font set: A collection of one or more fontsthat provide all the characters used by aparticular language.

foreign key: A primary key in one tablethat also exists in another table within

the same database. A foreign key con-sists of one or more attributes that canuniquely identify a record in the tablecontaining the primary key. The identi-fication and designation of foreign keysare automatic. (See also: database, field,primary key.)

form: See database form.

format: The preparation of optical, floppy,or hard disk media; a tape cartridge; orother storage media with basic locationalinformation so that the media can beused. Some manufacturers providepreformatted media for their specific de-vices, such as hard drives. Other genericmedia, such as floppy disks, are usuallynot formatted when purchased. Somemedia, usually those with a serial record-ing format, such as open reel tape, areautomatically formatted as they are used.

Fourier transform: A type of two-way fre-quency transform for identifying and re-moving unwanted spatial frequency com-ponents in an image. The Fourier pro-cess is normally used to identify and re-move systematic noise “spikes,” such asregular lines that may have been intro-duced by a faulty image collection de-vice. The process works as a two-wayoperation. First the forward transformcreates a pair of intermediate raster ob-jects that reveal abnormal data variabil-ity. After the values in those raster ob-jects have been edited to remove the dataspikes, the inverse transformation cre-ates a raster object with the same imageas the original, but with lines or othernoise removed. This Fourier Transformprocess has somewhat the same smooth-ing effect as the low-frequency TNTmipsimage filtering process.

frame: (video) A complete video imagewhich consists of two interlaced fields.Odd lines of the frame are contained inthe primary field which is alternated withthe secondary field that contains the evenlines. The primary field lasts 1/60 of asecond in standard broadcast video. Thesecondary field follows in the next 1/60of a second. The entire frame takes 1/30 of a second to display. There is adifference of 1/60 of a second betweenalternate lines in the image.


frame: (window) The border around a win-dow in TNTmips. The active window(where any typing or selecting of op-tions will occur) is indicated by a high-lighted or different colored frame.

framegrabber and framegrabbing: Back-ground: Prior to digital broadcasting,composite video and US standard broad-casts repeated each field every 1/60 of asecond. Two interlaced fields, each con-taining alternate lines of the image makeup one video frame that lasts 1/30 of asecond.

A video framegrabber is a microcomputerinterface board that accepts a video in-put signal and passes it to a color moni-tor. A program signals the video frame-grabber to both freeze and digitize onevideo frame.

Digitizing a video frame may transformeach picture element in the frame to asingle byte in the board’s memory. Morecommonly, it simultaneously captures,digitizes, and stores the video’s separatered, green, and blue color values. Someframegrabbers can be set to grab only asingle field to avoid the relative move-ment between a frame’s two fields. Ifthe video comes from a camera that hashigh-speed electronic shuttering (like 1/1000 of a second), movement in the 1/30 of a second between the primary fieldand the secondary field causes saw-toothed edges on alternate lines instraight features like road edges, and ver-tical poles.

As soon as the video is saved in the boardmemory (1/30 or 1/60 of a second), pic-ture motion on the monitor freezes (evenif the live video input continues) whilethe data in the board memory is con-verted into a display image. Then TNT-mips reads the memory of the board andtransfers the image into project file ras-ter objects.

Framegrabber boards should not be con-fused with video digitizing boards, whichgradually sample and construct a digitalrepresentation of a still scene video im-age. Sampling video boards represent anolder technology, but are still used fornon-standard, higher resolution videosources. (See also: video digitizing board.)

FSA: Farm Service Agency.

frequency transform: An operation thatbreaks down an image into its fundamen-tal spatial frequency components for sub-sequent analysis or filtering.

fuzzy C-means: An unsupervised classifi-cation or clustering process developed byRobert Cannon et al. and documented in:Robert L. Cannon, Jitendra V. Dave,James C. Bezdek, and Mohan M. Trivedi(1986) IEEE Transactions on Geoscienceand Remote Sensing. GE-24(3):400–408.Segmentation of a Thematic Mapper Im-age Using the Fuzzy C-Means ClusteringAlgorithm.

— G —GAC : Global Area Coverage.

gadget: A graphical X object, like a widget,that does not have a window of its own(as most widgets do) but appears inside aparent window.

gap: A line segment undershoot leaves a blankspace in the T-junction of two lines. Theraster thinning process often leaves gapsthat should be repaired by raster editingbefore final vectorization.

GEM: A window and mouse desktop operat-ing system developed and marketed in the1980's by Digital Research, Inc.

genlock: To synchronize two video signals(usually NTSC) to match the color videoframes. Genlocking is necessary to mixand combine two signals, like a live videoimage and a graphic overlay. Some dis-play boards can output an NTSC signalbut cannot genlock, or mix, that signalwith another video signal.

geocatalog: A geospatial catalog, or geocata-log, gives a geographic overview of allthe project materials in a selected direc-tory on your system so that you can findall the objects in the same location as theobject in your current view and selectthem if desired.

geocoding: See: georeference.

geodesy: Investigation of scientific ques-tions connected with the shape and di-


mensions of the earth.

geoid: The figure that represents the irregu-lar spheroidal shape of the earth is calledthe geoid. The geoid is an equipotentialsurface (which means the direction of grav-ity is perpendicular to all points on thesurface) at mean sea level. Because ofvariations in the distribution of the massand density of the earth’s constituents,the geoid generally rises over the conti-nents and is depressed in oceanic areas ;the geoid also conforms to various lumpsand depressions that depart from averagesmoothness on the earth’s surface. Formapping purposes, the attributes foundon the geoid must be transferred to a moreregular geometric surface, an ellipsoid.

GeoJP2: A file with JPEG2000 compressionand self-contained georeference informa-tion. No companion files are required toprovide without additional files to con-tain that information. (See also:JPEG2000 compression.)

GeoLock: A standard View window / Viewmenu option that can be used when morethan one View window is open. SelectGeoLock to open a menu where you canselect the position locking feature or thescale locking feature. When one of thelocking features is selected, all open Viewwindows change in concert based on yourlocking choice.

geomashup: A geomashup combines geospa-tial data (such as maps, images, and pointlocations) from multiple sources into asingle interactive web page display. Geo-mashups commonly show geodata for aparticular area or a particular theme andoverlay it on a global reference map orimage such as the proprietary map andsatellite layers offered by Google Mapsand Bing Maps. The Application Program-ming Interface (API) for Google Maps,Google Earth, Bing Maps, or OpenLayersprovides the geomashup with familiarcontrols for panning the view and zoom-ing through different levels of detail. Atileset structure is the most efficient wayto store geodata for a geomashup. Youcan create geomashups in TNTmips us-ing the Assemble Geomashup process. (Seealso: Assemble Geomashup, mashup,tileset.)

geometric layer: A vector, CAD, shape,TIN, or LAS layer composed of points,lines, and/or polygons.

geometric transformation (or rectifica-tion): A process in which an image isstretched differentially so as to changeits internal geometry is said to have un-dergone geometric transformation or rec-tification. A transformation specificallyrefers to the process of projecting animage from its plane onto another planeby translation, rotation, and/or scalechange.

georeference or geographic calibration:Information that relates raster cells orvector/CAD elements to a specified co-ordinate system or map projection. TheRVC file format keeps the informationneeded to relate every raster cell or vec-tor coordinate point to some geographiccoordinate system (like a particular mapprojection) in subobjects associated withthe parent object. Geographic calibra-tion may be established when creating anobject (like extracting an image mapfrom a Landsat or SPOT satellite im-age). Calibration can also be added to anexisting object either by entering con-trol points or by associating it with somecalibrated object (like overlaying a cali-brated vector to calibrate a raster). AnRVC subobject identifies a calibratedobject’s map projection.

georeferenced image map: See: imagemap.

geospatial intelligence: the exploitationand analysis of imagery and geospatialinformation to describe, assess, and visu-ally depict physical features and geo-graphically referenced activities on theearth.

geoviewer: The viewing component of lo-cal and web applications that view geo-located source materials via the Internet,such as Google Earth, Google Maps, BingMaps, World Wind, and TNTmips.

GIF: Graphics Interchange Format.

gigabyte, Gbyte, or GB: A computer unitof measurement for 230 (approximately)1,000,000,000 bytes, 1,000,000 kilo-bytes, 1,000 megabytes, or .001 tera-bytes. (See also: bit, byte, exabyte, kilo-


byte, megabyte, petabyte, terabyte,yottabyte, zettabyte.)

GIS: Geographic Information System. “AGeographic Information System is acomputer system designed to allow usersto collect, manage, and analyze large vol-umes of spatially referenced and associ-ated attribute data. The major compo-nents of a GIS are: a user interface; sys-tem/database management capabilities;database creation/data entry capacity;spatial data manipulation and analysispackages; and display/product generationfunctions.” — from USGS Open File Re-port 88-105 [A process for evaluatingGeographic Information Systems]. In thebroadest sense, a GIS is any integratedsystem of information that includes ageographic component.

global variable: (SML) All variables notexplicitly declared local are called “glo-bal variables” and are insulated from theoperations of a function or procedureonly if the function or procedure declaresa local variable of the same name.

glyph: Characters, letters, numerals, andsymbols that make up a font typeface.Glyphs can include alpha-numeric char-acters, ideographs, international currencysymbols, and directive symbols and iconssuch as curved arrows and dingbats.

gnomonic projection: A type of perspec-tive azimuthal map projection. The pointof the projection is the center of thesphere. Gnomonic is the only projec-tion on which all great circles representedare straight lines.

Google Maps: A free, online, 2D, web mapservice provided by Google. You canview map (roads), satellite, or terrain-with-map base layers. Extensive searchcapabilities are provided, inclding addresssearch for parts of the world. Route plan-ning is also available from Google Maps.Street View is another Google Mapsviewer, which supplies drive-by imagesfor an expanding number of cities (cur-rently in North America, Europe, andJapan).

Google Maps Tile Overlays: A “Tile Over-lay” is the name Google uses for the struc-ture of a tileset that is optimized for itsAPI to use as an overlay. It conceptu-

ally emulates the way in which Googlestores its proprietary satellite, terrain, androads base layers that are accessible overthe Internet. Tiles for areas of the sourceimage that are to be treated as completelycovered by the tile are usually *.jpg. Tilesare *.png where the area covered over-laps the regular or irregular outer edgeedge of the source image or an inner edgefor missing internal areas. All tiles canalso be *.jpg or all *.png depending uponthe desired appear of the source image inthe application.

GPIB: General Purpose Interface Board. Anolder interface standard for computers anda peripheral devices, such as a scanner,printer, or scientific instrument.

GPS: Global Positioning System. A networkof radio-emitting satellites deployed bythe US Department of Defense. Ground-based GPS receivers can automaticallyderive accurate surface coordinates for allkinds of GIS, mapping, and surveying datacollection.

gradient filtering: A method of edge detec-tion using two filters. One filter enhanceshorizontal edges and the other enhancesvertical edges. The results are then com-bined into a single output cell value. Gra-dient filtering usually produces better re-sults than a single high-pass filter. (Seealso: filtering)

Grain Shape Index: One of the 12 fuzzyproperties that can be calculated for vec-tor objects. The Grain Shape Index mea-sures shape with a minimum value ap-proximating two for long skinny poly-gons, pi for circles, and four for rectangles.The Grain Shape Index can be very largefor fractals. The equation for calculatingthis property is: Grain Shape Index =Perimeter / Long Axis.

GRASS: Geographic Resources Analysis Sup-port System. A public domain GIS systemdeveloped at the U.S. Army’s Construc-tion Engineering Research Laboratory inUrbana, Illinois. It is now managed bythe GRASS Development Team. The sys-tem was designed for minicomputers andhas since been implemented on variousmicrocomputers. It is a raster-based sys-tem that can interface to vector data setsfor data preparation and import/export.


graticule: A network of parallels and merid-ians for equal intervals of latitude and lon-gitude on the earth’s surface. The formand appearance of a graticule depends onthe map projection employed. The linescomprising a graticule may form a square/ rectangular network; a graticule mayalso be comprised of two families of curveshaving variable separation between them.The mathematical framework of a mapis comprised of a grid, or a graticule, orboth. A grid is always comprised of asquare network of parallel lines represent-ing particular linear distances on theground.

gray out: To dim a label that is nonfunc-tional / unavailable in current context.

graytone or grayscale: An image or rasterobject that contains tone levels and in-tensities that grade gradually from black(no intensity) to white (high intensity).Differences between one tone level andanother correspond to differences be-tween one data level and another.

graytoned image or raster: An image orraster object that contains tone levels andintensities that grade gradually from black(no intensity) to white (high intensity).Differences between one tone level andanother correspond to differences betweenone data level and another.

great circle: “A circle on a spherical surfacesuch that the plane containing the circlepasses through the center of the sphere”(Random House). For example, the equa-tor is a great circle.

greeking: An on-screen substitution, suchas a wide gray line or an empty box, forgraphic text that is too small to be drawnand viewed distinctly.

green biomass or phytomass: The amountof wet weight or dry weight of growing,chlorophyll-containing plant material perunit ground area. It is usually expressed ingrams per square meter, tons per acre, ormetric tons per hectare.

greenness: The biophysical property of thesurface of the earth that indicates its green-ness in a biological sense and gives a quali-tative estimate of green biomass. It mea-sures plant vigor, water wellness, and chlo-rophyll content. Greenness can be com-

puted from Landsat MSS or TM imagesand stored in a raster object by Kauth’sgreenness, brightness, wetness transfor-mations.

ground control: Targeted terrain surfacefeatures, such as road intersections, ofknown (surveyed) horizontal and verti-cal coordinates used to orient and other-wise relate airphotos and satellite imagesto a map projection.

ground range: The horizontal distancealong the ground for the flight path of aside-looking radar system. Ground rangeis calculated by converting slant rangeusing raster resampling and the flight pa-rameters to correct the geometric dis-tortions in the raw geodata.

ground resolution: The limit of detail clar-ity in an image of the earth’s surfacecollected by some remote sensing device,usually measured in meters. An imagewith a ground resolution of 10 metersshows no ground features smaller than10 x 10 meters. Each data cell in such animage contains a value for a distinct 10 x10 meter surface area.

ground truth: Information collected at thesame site and at the same time as a re-mote sensing system is collecting data.Ground truth is considered more accu-rate, and is used to interpret and cali-brate remotely sensed observations.

group or display group: Each view win-dow in the TNTmips display process caninclude multiple groups of objects, andeach group can contain multiple layersof objects. Groups allow side-by-side dis-play of related items in a single window.TNTview does not provide group han-dling tools, although you may encountergroups as part of a display layout savedin TNTmips.

group list: A list in the control window ofthe display process that shows the cur-rently defined groups.

GUI: Graphical User Interface. A systemprogram that provides windows and iconsand a way for the user to manipulatethem with keyboard and mouse. In theX Window System, the GUI is a clientand not part of the X server. Thus sev-


eral different GUI’s are possible under X.TNTmips uses the LessTif GUI.

— H —handles: A tiny square used to mark a se-

lected graphic (non-textual) element atthe corners or along the edges. Handlescan be dragged with the mouse to moveor resize the selected element.

Hangul: Korean alphabetic system of writ-ing created in the fifteenth century.

hanzi: Traditional written Chinese charac-ters which are not strictly tied to thespoken language to the extent that mu-tually unintelligible Chinese dialects (suchas Mandarin, Wu, Hakka, Cantonese) usethe same written forms.

hardcopy layout: A layout designed specifi-cally for printing.

hard disk or hard drive: A mechanical,magnetic storage device for computerdata and program files. Internal harddisks (sometimes called fixed disk) aremounted inside the computer chassis andso are not removable. An external harddisk is an enclosed unit that is linked to acomputer by appropriate connectingcables. Hard disks are much faster andhold much more than a removable floppydisk, but are slower than RAM disks. (Seealso: floppy disk, RAM disk.)

hardware key or software license key:A small device that contains sealed cir-cuitry and is attached to a microcom-puter (as through a USB, parallel, or se-rial port) to verify and authorize soft-ware and hardware system configuration.TNTmips will not run on a microcom-puter that does not have a valid hard-ware key.

hatch pattern: A polygon fill pattern com-posed of line elements, rather than abitmap. The line elements can be asimple, solid color or a more complexline pattern. The area between line ele-ments is transparent.

HBS: A method of defining color space,sometimes known as HSV, that combineshue, brightness, and saturation compo-

nents to produce all colors. An HBS ras-ter set in TNTmips is a set of three ras-ters with the same dimensions that repre-sent the hue, brightness, and saturationcomponents of an image.

The hue-brightness-saturation model usesa six-sided pyramid (or hexcone) with theapex at the bottom to describe the col-ors. Black is at the point of the hexconeand the purest, most intense colors are atthe top of the hexcone. Like the HISmodel, on any horizontal slice of the cone,the hue varies as you move around theslice and the saturation increases as youmove outward from the center. The HBSmodel may be more intuitive than theHIS model, because the Brightness factoris at its most intense at 100%, rather thanthe Intensity factor which is most intenseat 50%. (See also: HIS, RGB.)

HelpTip: Pop-up information that tells auser how to proceed when using an APPLIDAT

developed using TNTmips. The text fora HelpTip is stored as a subobject underthe SML script for the APPLIDAT. This textfile also specifies the delay and colorscheme for the HelpTip.

HI:See: HyperIndex.

hierarchical picklist: A picklist that isgrouped by the values in another databasefield.

hierarchical tileset: The common popularweb geoviewers use hierarchical tilesetswhere a collection of subdirectories ineach directory contain all the tile filesfor one prerendered zoom level. Thesedirectories are all arranged pyramid-stylewhere each directory at a given level rep-resents a portion of the image at thatlevel’s scale or zoom. MicroImages’ in-ternal tileset raster objects use a hybridapproach combining both flat and hierar-chical structures.

high-boost filter: A process that enhancesand sharpens spatial features in a con-tinuously varying raster object. (See also:filtering.)

highlight: A temporary color change to in-dicate attention to an element, such asmouseover highlight.

high-order characters: Characters in acomputer’s 8-bit character set above the


standard 128 ASCII characters. High-or-der characters (also called “extended”characters) are numbered 128-255, andmost PC’s use the IBM extended charac-ter encoding scheme (also called the PC-8 character encoding scheme) for screendisplay of the high-order characters.

The mapping of the high-order charac-ters to the text-mode character encodingscheme of a particular printer is not stan-dard. In order to see what characters aprinter provides for the high-order char-acters, consult the printer’s documenta-tion or generate your own test page. Insome application software, in order toget a printer to generate a particular char-acter, you may have to use a differentcharacter on the screen.

high-pass filter: A process that enhancesand sharpens the boundary edges in thespatial features of a continuously varyingraster object. (See also: filtering)

hiragana: Cursive form of kana.

HIS: Hue, Intensity, and Saturation. Some-times called HLS, for Hue, Luminance andSaturation. The system of defining videooutput color from hue, intensity and satu-ration characteristics. HIS controls arecommonly used with color television sets.Most computer displays use RGB (red/green/blue) color mixing information in-stead.

The hue-intensity-saturation color modeluses a double cone (with its greatest cir-cumference at the midpoint of the z-axis)to describe specific colors. On any hori-zontal slice of the cone, the hue varies asyou move around the slice and the satura-tion increases as you move outward fromthe center. Intensity is the z-axis of themodel. The shades of gray are found alongthe z-axis, where hue and saturation equalzero. (See also: HBS, RGB.)

histogram: A graph of the number of timesa value occurs across a range of possiblevalues. One axis of a raster histogramshows how many times a cell value isfound in the raster. The other axis showsthe range of possible data values (like 0 to255 for 8-bit cell values).

home range: The area defined by a swarmof spatial observation events. Classically,the home range is the area defined by wild-

life sightings that an animal or commu-nity of animals uses under normal condi-tions. Environmental stresses may causea preferred home range to shrink, en-large, or be abandoned.

horse latitudes: The range of latitudes fromapproximately 30–35° N and S over theoceans characterized by hot and dryweather and calm or very light winds.

hot spot: See: symbol hot spot, cursor hotspot.

HPGL: Hewlett Packard Graphics Language.A protocol language used by a number ofpen plotters.

HTTP: Hypertext Transfer Protocol.

hue: One of the three coordinates neededto specify a color in the HBS and HIScolor domain. Hue tells the color such asred, blue, or green. (See also: HBS, HIS.)

hull: A hull is the two dimensional area forwhich a TIN is generated. Within thehull, including its edges, the Z value atany X-Y position can be interpolated. Ahull is convex when all lines that con-nect two points on the hull boundary fallentirely within the hull. A hull for a U-shaped area, for example, is not convex.

hydrography: The description and studyof bodies of water or their representa-tions on a map.

HyperIndex® or HI: A TNTmips processthat creates and manages large collec-tions, called stacks, of graphically indexedobjects (raster, vector, CAD, text anddatabase objects). You can retrieveHyperIndexed images and informationfrom the object hierarchy by selecting afeature of interest (or “index area”) inthe current display image with the mouse.(See also: index area, stack.)

hyperspectral image: Imagery acquired byhyperspectral remote sensors that col-lect image data simultaneously in dozensor hundreds of narrow, adjacent spectralbands. (See also: mulispectral image)

hyperspectral object: A hyperspectral im-age can be stored in a TNTmips ProjectFile in one of two ways: as a set of sepa-rate raster objects with one object foreach wavelength band or as a singlehyperspectral object, or hypercube, that


includes raster value and wavelength in-formation for all the bands in ahyperspectral image.

hypsography: Measurement and mappingof the variations in earth surface eleva-tion in reference to sea level, which areoften represented by contour lines onmaps.

— I —ICC: International Color Consortium. The

ICC developed the profile formats usedto tell hardware devices how to producesRGB colors.

ICM: Image Color Matching or IntegratedColor Management. Also the file exten-sion used by Microsoft Windows for pro-file files.

icon: A stylized representation of an objectthat consists of an image and a label. Awindow icon is a minimized representa-tion of a window or window family usedto help organize windows and tasks inthe display. Iconifying a window changesnothing about the state of the active pro-cess in the window.

icon button: A button with a simple pictureand a ToolTip to identify its function,which is usually found on a toolbar butmay be found in isolation in some soft-ware products.

ideograph: A symbol that represents mean-ing without indicating pronunciation.Often opposed to “phonetic.” Chineseis often, but erroneously, called an ideo-graphic language. Its origins (like thoseof Western alphabets) were ideographicand pictographic, but it is more accu-rately described as a “morphosyllabic:” acombination of syllabic characters withnonphonetic techniques, such asdeterminatives, to suggest the meaningcategory of written items.

IDIMS: A minicomputer, raster-based im-age processing system originally devel-oped by NASA then sold to TRW andthen to Terra-Mar and ported to the PC.

IEEE: Institute of Electrical and ElectronicsEngineers.

IETF: Internet Engineering Task Force.

Ikonos satellite: A satellite that collects highresolution imagery providing 1m panchro-matic or 4m multispectral imagery. Apan sharpened multispectral product isalso available.

image: Any analog or digital two-dimen-sional array of values whose spatial inter-connections convey useful information.Image has a wider sense than photographs,TV, or human vision. A photographicprint is an image but an image is not nec-essarily a photograph. What a humansees can be called an image but image isnot restricted to describing human vision.The raster scan of a color map is an im-age until it is reduced to a vector object.However, the display of a vector objecton the monitor creates an image of thatvector file. Properly, that which is storedin a raster object can be called an image,but that which is stored in vector, text, ordatabase objects cannot.

image map or georeferenced image map:An image that has been processed to belike a map in appearance, scale, geom-etry, boundary, and projection with a de-gree of precision that satisfies the user.Measurements made from an image mapyield results equal to those made from thecorresponding planimetric, topographic,or other map. Similarly, either the imagemap or the conventional map can be over-laid and matched with the other.

For example, a 7.5' image map preparedin TNTmips from Landsat or SPOT sat-ellite images will accurately match thecorresponding USGS topographic map.Similarly, the color scan of a topographicmap that has been assembled by tiling andcalibrated to map coordinates is an imagemap. (See also: nominal image map.)

impedance: The opposition to flow along agiven line; that is, the cost of travelingalong a given line.

impedance limit: The maximum imped-ance allowed for any path to a center inthe allocation mode of the NetworkAnalysis process.

implied georeference: A georeference thatuses geographic coordinates as elementcoordinates (object coordinates = geo-


graphic coordinates). Vector, CAD, andTIN objects can have an impliedgeoreference.

importing vector, CAD, or raster objects:Decoding the raster data values or thevector/CAD coordinates in anothersystem’s format and converting them toTNTmips project file objects. Colorschemes; arc, node, and polygon struc-tures; geographic calibration; and all othersupporting data is converted into the ap-propriate subobject as long as their for-mat can be decoded from their developer’sinformation or determined from samplefiles by MicroImages.

index: Special data structure used in a data-base to speed searching for records or spa-tial features in geographic data sets.

index areas: The regions in a HyperIndexparent object linked to a daughter object,which may be rectangular, circular, orquadrilateral in shape. HyperIndex willdisplay the daughter object when themouse selects a point within the indexarea. Active index areas can be revealedon the display of the parent object whenthe option “Show Index Areas” under theView window menu HyperIndex is on. (Seealso: daughter object, link, parent object.)

infinite loop: see loop, infinite.

INFO: The database program used by ARC/INFO. (See also: ARC/INFO.)

input redistribution: Automatic redistri-bution (rescaling) of the cell values in eachinput raster object prior to classificationin the Auto-Classify process.

integer: A number without a decimal, such as0, 8, and -3.

intensity: One of the three coordinatesneeded to define a color in the HIS colordomain. Intensity represents a color’sbrightness or average radiance level. In-tensity data is very similar to the infor-mation in black and white representationsof color images. (See also: HIS)

interactive line-following: The Interac-tive Line-Following process lets you in-teractively trace easily distinguishable linesin a RGB, or color separated, type rasterobject and create vector (or CAD) ele-ments with minimal guidance. Interac-tive Line-Following is a tool available in

the TNTmips Object Editor used to cre-ate vector or CAD lines.

interface: The type of signal protocol forconnecting computer devices. You canonly connect a peripheral device to amicrocomputer through a matching in-terface. Common interface types includeserial, parallel, SCSI and GPIB.

interface card: Any electronic circuit boardinstalled in a microcomputer that handlestranslation between the computer andsome particular hardware device. For ex-ample, an interface board may translateoutput data into display signals for animage display monitor, or translate in-put signals from a color scanner into digi-tal data for the computer.

interlaced video: Background: The im-age you see on a TV screen is made froma set of about 480 horizontal lines. Thelines are projected in two passes of thesignal beam. Each pass only projectsevery other line of the image: the oddlines in one pass, and the even lines inthe next pass. One scan takes 1/60 of asecond, so the whole picture (the frame)is refreshed every 1/30th of a second.There is a time difference of 1/60 of asecond between any pair of adjacent linesin a frame.

Thus, a single, still video image of 1/30of a second duration consists of two in-terlaced fields of the source video signal.Displaying a single frame of interlacedvideo causes vertical jitter. This jitter isespecially pronounced when an imagecontains horizontal lines. This is calledumpire shirt jitter on conventional broad-cast TV and can be seen along the blackand white edges of an umpire’s shirt oralong the sharp horizontal edges of largeletters. This effect can cause eye strain.Interlace jitter is best overcome by usinga monitor with long-persistence phos-phor. This phosphor holds each linelonger until it can be refreshed by thenext scan.

internal database: A database created by aTNT product maintained in RVC format.(See also: database object, external data-base file.)

internal tables: Information that is auto-matically created in the TNT products


for vector, shape, and TIN objects andsome raster types, but is not shown bydefault with the user-defined tables. In-ternal tables include internal object in-formation, which is not actually main-tained in tabular form but is provided sothat you can view the standard, internalinformation for each and every elementin vector, shape, and TIN objects andfor each cell in some raster object types.Each element type in vector, shape, andTIN objects has its internal table. Inter-nal tables are not available for CAD ob-jects because they require referencing byelement number

The internal tables keep track of all to-pology information for vector elements,what elements are connected in TIN ob-jects, and element numbers in directlydisplay shapefiles. To view internaltables, use the Show System Tables rightmouse button menu option at the ele-ment level of a layer manager window.(See also: system tables.)

internationalized X application: A pro-gram for the X Window System that isnot “hard wired” to any specific languageor culture, and so is capable of operatingusing a single user-selected language andset of cultural conventions. The TNTproducts can be used in any language andscript in the world.

Internet: a global comptuer network con-sisting of thousands of networks typi-cally interconnected by fiber optic ca-bling. It had two parent networks whosejoining began the ongoing evolution: (1)U. S. Military (Tactical communicationin the event of telephone downtime dur-ing wartime) (2) Academics (Shared in-formation between researchers).

interpolation: Applying mathematical es-timation techniques to sets of numbersto find intermediate values. Interpola-tion is a collective term for various tech-niques of determining an approximatevalue of a function at a point in the do-main between given points at which thefunction values are known. Bilinear in-terpolation, for example, is based on thepresumption that the value being soughtlies on or near a straight line joining twoknown values. (See also: convolution.)

interpretation: Identifying and groupingclasses of features in an image. TNT-mips provides three kinds of interpreta-tion processes: Interactive (Feature Map-ping), Automatic (simple clustering, K-means, fuzzy C-means, and minimum dis-tribution angle), and Semiautomatic(maximum-likelihood ratioing, stepwiselinear discriminant analysis, and Suits-Wagner classification). In a fully inter-preted image, every pixel is assigned to aclass. In many cases, partial interpreta-tion is adequate, such as just showing cul-tivated land, or just showing wetlands.

interpreted programming language: (asopposed to a compiled language) A com-puter language that is evaluated and ex-ecuted by the system one command orstatement at a time. By contrast, a pro-gram in a compiled language is completelyevaluated and translated into machinecode by the system before any of it isexecuted.

intersection: A merging of two vector ob-jects such that only the elements in theshared area of the two objects are copiedto the resulting vector.

inverse distance: Value used in some statis-tical calculations and equal to one dividedby the distance between two points ofinterest.

ISA: Industry Standard Architecture. One ofthe bus architectures for microcomputersused in PC/XT and PC/AT. Replaced in1993 by Plug and Play ISA (See also: bus.)

ISO: International Organization for Stan-dardization. The ISO defines and pub-lishes standards that can be adopted bymany manufacturers. For example, oneISO standard defines the format for eras-able optical disks, so they can be used ondrives from any manufacturer that sup-ports the standard.

ISO 10646: A character encoding schemethat is a super set of the ASCII, Latin-1,and Unicode character sets that has roomfor 4,294,967,296 characters (a 32-bitor 4-byte character encoding scheme). Ul-timately, ISO 10646 will assign codes toevery known symbol and character ofboth modern and ancient languages.

ISODATA: Iterative Self-Organizing DataAnalysis. An unsupervised classification


method in the Auto-Classify process.

isoline: A line connecting points of equalvalue. Examples are contour lines andlines depicting ocean temperature gradi-ents.

item: Anything that can be placed on thepage in the page layout design process,including rasters, vectors, CAD objects,text files, scale bars, and tick marks. Thepage layout process provides tools to se-lect, size, and position items.

— J —Java: A simple, platform-independent pro-

gramming language for writing applets,which are obtained by a client from theInternet and run on the client’s machine.

JavaScript: Netscape’s simple, cross-plat-form, Internet scripting language that runsin a limited number of environments.

JPEG: Joint Photographic Experts Groupresponsible for the standards for still im-age compression formats, such as JPEG,JBIG, and JPEG 2000.

jumper: A physical connector on a micro-computer circuit board that bridges twoneighboring terminal posts. The jumperis either slid down onto the posts or re-moved according to the configuration op-tions described in the documentation thatcame with the device.

— K —K or KB: See: kilobyte

kana: Japanese syllabic characters derivedfrom Chinese. There are two varieties:hiragana and katakana.

kanji: Japanese term for Chinese charac-ters.

katakana: Angular form of kana, roughlyparallel to Latin block letters, and usedmuch like English italics.

Kauth’s Tasseled Cap or Kauth’s green-ness / brightness / wetness: A set of

linear combinations of the Landsat TMspectral bands which computationally re-duce the images to maps of a site’s green-ness, brightness, and wetness. Kauth, ascientist at the Environmental ResearchInstitute of Michigan, extended the greenbiomass concepts developed by Dr. LeeD. Miller, a principal of MicroImages,to extract more biophysical informationfrom Landsat MSS and TM multispec-tral images. He developed the combina-tions by carefully correlating ground mea-surements made by Miller and others withvalues in the satellite images. The plotsof the data distribution in the originalspectral bands resemble a tasseled cap —hence the general name by which thesetransformations are called.

key field: A field in a database table identi-fied as of importance is designated a pri-mary key. There can be only one pri-mary key in a table. A primary key fieldmust have unique entries for each recordin the table. A primary key field also maynot be blank in any of the records in atable. A foreign key is a field with thesame name as a primary key that is lo-cated in a different table. Foreign keysare identified automatically when pri-mary keys are designated in other tablesattached to the same vector/CAD ob-ject. (See also: database, foreign key,primary key.) Primary and foreign keyrelationships between tables let you es-tablish computed fields that incorporatevalues from more than one table in theirdefining expression.

kilobyte: A unit of measure equal to 1024bytes (2 to the 10th power), but looselyused for 1,000 bytes. So also with itsmultiples: megabyte (loosely 1,000,000bytes), gigabyte (loosely 1,000,000,000bytes) and terabyte (1,000,000,000,000bytes). (See also: bit, byte, exabyte,gigabyte, megabyte, petabyte, terabyte,yottabyte, zettabyte.)

K-means: An iterative method of unsuper-vised classification (clustering). The n-dimensional raster space is divided intoK clusters. The cluster means are used todetermine cluster membership. After allcells are processed, new cluster meansare determined and the process is repeated


a predetermined number of times or un-til convergence is achieved.

KML: Keyhole Markup Language. Thesefiles are used to provide overlays inGoogle Earth and Google Maps. You canrender any display in the TNT productsto KML for viewing in combination withtheir native imagery.

Kuan (Adaptive Noise Smoothing) fil-ter: Filter that removes speckle fromradar images using a minimum meansquare error calculation to estimate thevalue of the true signal for the centercell in the filter window. The filter thencalculates the signal estimate from thelocal mean and variance and the noisestandard deviation.

Kuan (MAP): Kuan Maximum A Posterifilter; this filter removes speckle fromradar images using a maximum likelihoodprobability approach to estimate the truesignal value for the center cell in thefilter window. The filter then maximizesa probability function involving the cen-ter cell value, the local mean and stan-dard deviation, and the noise standarddeviation.

— L —label: (CAD context) A CAD element that

contains text used to identify a point,line or polygon element.

label: (vector context) Text in a vectorobject used to identify a point, line, orpolygon element. TNTmips can createlabel text automatically from attacheddatabase tables. Also, you can manuallyassign arbitrary labels independent ofclass membership that need not be asso-ciated with individual elements.

label: (window context) The static text partof a component that presents informa-tion to the user about that component,such as the action invoked by a push but-ton or the mode selected by a check but-ton.

labeling: (raster context) Identifying andgrouping the clusters that result from anykind of automated image interpretation.

You choose labels (names for types offeatures) based upon your knowledge ofthe areas or materials in the image. Usethe TNTmips Feature Mapping processto label (and possibly combine) the clus-ter map output of automatic image inter-pretation processes.

LAI: See: leaf area index.

LAN: Local Area Network.

land cover: The materials that cover a studysite, such as vegetation, bare soil, rock,sand, and water.

Landsat satellite: A satellite that collectsmultispectral images. At various times ituses 1) a Return Beam Vidicon (RBV) de-vice, 2) the Multispectral Scanning (MSS)device, and 3) the Thematic Mapping(TM) scanning device. Landsat also re-lays data from ground observation sta-tions. Landsat was originally called theERTS or Earth Resource Technology Sat-ellite.

LAS: The file extension for LiDAR data.Also the file extension for latitude-shiftfiles used in TNTmips by one of the geo-detic conversion methods.

Latin alphabet: The character encodingscheme used by most Western nations,based on the alphabet developed in Ro-man antiquity, itself a derivative of theGreek and Western Semitic alphabets.The Latin alphabet is used by the lan-guages of Western Europe, including En-glish, as well as many other languages suchas Turkish, Swahili, and Vietnamese. TheLatin alphabet is sometimes referred toas the Roman alphabet, but “Roman” isnot used in this discussion so as to avoidconfusion, since the term “Roman” is of-ten used in typeface and character stylecontexts.

Latin-1: (also known as ISO 8859-1) Asuper set of the 7-bit ASCII character en-coding scheme that includes various sym-bols plus letters with diacritics commonlyused in European languages. Latin-1 is an8-bit character encoding scheme, contain-ing 256 characters. Latin-1 makes dif-ferent assignments for codes 128-255than does PC-8. Latin-1 is, however, con-sistent with the Unicode and ISO 10646standards, and is the common encodingscheme used by Unix systems.


latitude: The angular distance in degrees ofa point on the earth north or south of theequator.

layer: A display entity comprised of one ormore components that can be manipu-lated separately from other layers. Thereis often a one-to-one correspondence be-tween layers and objects in TNTmips, butan individual layer may be comprised ofmultiple objects, such as the red, green,and blue components used to create asingle layer in multiple raster display. Eachgroup in the TNTmips display processmay be composed of multiple layers ofobjects. The background layer may beoverlaid by a raster object, such as anairphoto, which may in turn be overlaidby layers of CAD and vector objectswhich show soil boundaries, roads, or pin-mapping symbols.

layer list: The layer area of the control win-dow in the TNTmips display processshows the objects and drawing order ofthe current layers.

leaf area index or LAI: A unit-less, biologi-cal measure equal to the ratio of the one-sided surface area of the leaves in an insitu crop, forest, or grassland canopy tothe ground area.

least squares: A mathematical method forfitting a line or curve to a set of datapoints. Least squares minimizes the sumof the squares of the error term at eachpoint.

legend: The area on a map that provides akey to the colors, patterns, and symbolsused in the map.

level: In HyperIndex, any object or file thatis displayed in the Display / Spatial Datawindow is called a level. A level may origi-nate from a raster, vector, or CAD ob-ject. However, in HyperIndex, the levelassumes an identity beyond that of theobject or file itself, because the level in-cludes the index areas that have been de-fined and any links to other objects. Thus,in addition to being an image, a level letsyou access many different kinds of infor-mation. (See also: HyperIndex, index area,link, stack.)

limit line: An adjustable graphic line on aprocess control screen that defines theboundary between values that are used and

values that are not used in the process.

l ine: (raster) One horizontal row of cells(or pixels) in a raster object (or displayimage). (vector, CAD) An ordered set ofcoordinates that represents a linear fea-ture (see: line element).

linear contrast: See: contrast.

linear transform: (map registration) Onekind of map registration subobject(Regist) that contains an object’s math-ematical representation for its calibra-tion solution (least squares) derived froma control point list.

line element: One of the types of ele-ments that make up a TNTmips vectorobject. A line is defined by an orderedstring of coordinates, which define acurved path in space. Line attributes in-clude:Vector element class attributes may becross-indexed to a list containing the el-ement drawing style, which may includepolygon fill pattern, line drawing pat-tern, point symbol, line width or sym-bol/point size, RGB color, RGB labelcolor, RGB fill color, label font number,label font size, label font zoom factor,label font style, and label rotation angle.

line pattern: The drawing style of a linefor display or printing. TNTmips letsyou create and assign line patterns tovector and CAD line elements by class.You can control the width, color, anddesign (dashes, outlines, center stripes).Line patterns can be designed from the64 standard colors plus transparent (sothe underlying image shows through).

link: (to external database or raster object).A project file link to an external data-base file contains the file name, devicelocation, and field/record informationabout the database file. When a TNTproduct accesses the database, it dependson the link information to find and ma-nipulate the information containedtherein. If an external system moves orrestructures the database, the project filelink must be created again. A project filelink to an external raster format con-tains the file name and path. For themost part, linked raster files are treatedjust as internal raster objects. Subobjectscreated for use in the TNT products, such


as histograms and pyramids, are storedwith the project file link.

link: (HyperIndex). The relational con-nection between a region (or index area)on a parent object and daughter object ina HyperIndex stack. When a user clickson an index area on a parent object, thelink tells TNTmips how to retrieve thedaughter object on the next level. Theuser who creates the HyperIndex stackdefines the links as the stack is built. (Seealso: daughter object, HyperIndex, indexarea, parent object, stack.)

list box: A scrollable list of options fromwhich to choose.

local engineering: A type of georeferencethat relates one obect to another with-out specifying a Coordinate ReferenceSystem or relating it to a position on theEarth.

local variable: (SML) Variables that be-long to a function or procedure and existonly for that procedure are “local vari-ables.” No variable is local unless it hasbeen explicitly designated so with the“local” statement in the function or pro-cedure. A local variable may have thesame name as a variable used elsewherein the program without affecting it.

locale: One collection of data that definesthe semantics for a specific language andset of cultural conventions. Standard Cprovides a Locale structure which includessix aspects of the local culture and lan-guage: 1) Collation / sort sequence forcharacters, 2) Character type, 3) Moneyand currency symbols and formats, 4)Numerical formats: a point or commafor decimal demarcation, 5) Time -names of the weekdays, 6) Messages -yes/no, program status and prompts.

localization: Providing the run-time datathat describes the necessary elements ofa locale for an internationalized programso it can use the correct character en-coding scheme, font, keyboard conven-tions, collation sequence for the alpha-bet, and so on.

longitude: The angular distance in degreesof a point on the earth east or west ofthe Prime Meridian.

look angle: The direction an antenna of a

radar sensor is pointing when transmit-ting and receiving for a particular cell inan image.

loop, infinite: see infinite loop.

low-pass filter: A process that smoothes orreduces the spatial variability or detail ina continuously varying raster object. (Seealso: filtering)

LSCV: Least-Squares Cross Validation. Astatistical method.

— M —manifold: The 3D surface defined by the 3D

control points assigned to the vector orraster object onto which the vector orraster object is then projected. Used in-terchangeably with manifold surface.

mapping unit: See: soil mapping unit

map projection: “A device for representingall or part of a rounded surface on a flatsheet. Since this cannot be done withoutdistortion, the cartographer must choosethe map characteristic (area, shape, scale,direction) which is to be shown accuratelyat the expense of others.” Map Projec-tions Used by the U. S. Geological Sur-vey, Geological Survey Bulletin 1532, Sec-ond Edition, U. S. Government PrintingOffice, Washington, D.C., 1982, p. 5. Themap projection geometrically or math-ematically generates the grid of lines oflatitude and longitude.

Every process that establishes or trans-lates map projections offers the same stan-dard selection list of projections. Thepractical choice of map projections forungeorefer-enced project materials is nor-mally determined by the kind of projec-tion used by those project materials thatare calibrated to a projection. For ex-ample, if you have a scanned USGS topomap in the polyconic projection, you maydecide to calibrate (or translate existingcalibration) satellite images and vectoroverlays to the same projection. (Seealso: ellipsoid.)

map quadrangle or map quad: The geo-graphic area covered by a map. One kindof map quadrangle is the 7.5' x 7.5' area


that is covered by a standard USGS 7.5'topographic map. Referring to a 7.5' mapquadrangle does not imply the presenceof an actual paper map. The term maysimply designate the area covered by elec-tronically stored materials.

map scale: The relationship that exists be-tween a distance on a map and the corre-sponding distance on the earth. It maybe expressed as an equivalence, one inchequals 16 statute miles; as a fraction orratio, 1:1,000,000; or as a bar graph (sta-dia bar) subdivided to show the distancethat each of its parts represents on theearth.

map scale control: The ability to turngroups, layers, and elements on and offdependent on the map scale of the dis-play.

marking features: Saving prototype areasthat have been classified in feature map-ping, clustering, or some other TNTmipsinterpretation process as permanent fea-tures. Marked features can be unmarked.(See also: labeling)

mark: To select one or more of a group ofelements in preparation for acting uponthem by some program operation such asmove, copy, edit, open, analyze, display,or delete.

mashup: (software) A web page or applica-tion that combines features from morethan one source into an integrated expe-rience typically using an API to acquirecontent developed by others. For ex-ample, TNTmap Open that uses an APIfrom OpenLayers and the extendedGoogle Maps that launches from TNTmapBuilder and uses the Google Maps API.

mask or data mask: A processing barrier orboundary that only allows selected datavalues (perhaps in a chosen range or area)to pass. Users might choose a data maskthat blocks all values outside a selectedvalue range, eliminating all image featuresexcept those in the range they want touse in a process. A mask is more oftenused to confine the effects of a process toa selected area of a raster object. (Seealso: processing mask.)

matte: The background, surrounding area, andborder for a group, primarily legends, in alayout.

maximum-likelihood classification: Asupervised image processing routine usu-ally applied to multivariable images thathave a dimensionality greater than 3.First, the user selects sample areas, (calledprototype or training set areas) for eachfeature to be mapped. The maximum-likelihood process then computes the sta-tistical properties of these features. Simi-larly, it determines the statistical char-acteristics which separate feature types.After this identification model has beenbuilt, the process tests each cell to deter-mine in which prototype group it mostprobably belongs. A threshold can be setso that if the highest probability of afeature match is below the threshold, thecell is designated as unknown. This“catch-all” group insures that a cell rep-resenting a feature type not defined inone of the training sets will not be forcedinto membership.

maximum movement for steadiness:greatest allowable movement of locationsof class centers in each iteration of theAuto-Classify process. Specifying maxi-mum movement for steadiness in thisprocess limits the number of iterationsof the process.

maximum zoom level: The maximumzoom level or most detailed zoom levelcontains the tiles that provide the maxi-mum detail in content that is available inthe source image or map. It sets themaximum resolution at which the areacovered by the tileset can be viewed. Atileset must use predetermined zoom lev-els and thus the source image or map isunlikely to match any of these zoomlevels in detail or resolution. Thus themaximum zoom level is usually set to bethe zoom level that is the closest matchat a higher resolution or detail to theresolution of the source image or map.

MCA: Micro Channel Architecture. The32-bit bus architecture introduced for80386 IBM PS/2 machines in 1987.

medium Average or middle; a choice forsmoothing options in some TNTmipsprocesses.

megabyte, Mbyte, or MB: A computer unitof measurement for 220 or (approxi-mately) 1,000,000 bytes, 1,000 kilobytes,


.001 gigabytes, or .000001 terabytes.(See also: bit, byte, exabyte, gigabyte,kilobyte, petabyte, terabyte, yottabyte,zettabyte.)

menu: A pulldown or popup list of selectionoptions.

menubar: A graphic component at the topof a window that displays the titles ofthe pulldown menus.

meridian: A great circle on the earth’s sur-face that passes through the terrestrialpoles. All locations on the circle havethe same longitude.

message box: A type of dialog box thatcontains a message or warning provokedby a user request or processing condi-tion. The user must respond (for ex-ample by selecting the OK push button)before the interrupted process can re-sume.

metadata Information stored in a subobjectattached to an object. This informationcan includes the source of the geodata inthe object, the date the image was cap-tured, the scale of the image, the loca-tion of the image, and so forth.

MI: MicroImages, Inc.

MICROPIPS: An early raster-based micro-computer image processing system.

MIDI: Musical Instrument Digital Interface.

MIME: Multipurpose Internet Mail Exten-sions.

minimum distribution angle: An unsu-pervised classification or clustering pro-cess developed by Dr. Jack Paris and pre-sented in: Jack F. Paris and Helenann H.Kwong (1988) Photogrammetric Engi-neering and Remote Sensing 54(8):1187–1193. Characterization of Vegetationwith Combined Thematic Mapper (TM)and Shuttle Imaging Radar (SIR-B)Image Data.

minimum zoom level: For tilesets, theminimum zoom level, or least detailedzoom level, contains the tiles that pro-vide the most synoptic or overall viewof the area covered by the tileset. It isthe lowest resolution at which the areacovered by the tileset can be viewed.

min/max box: A rectangle that encloses avector or CAD element such that the

edges of the box indicate a minimum ormaximum coordinate value for that ele-ment.

minute or ': “The sixtieth part of a degreeof angular measurement, often repre-sented by the sign ‘ as in 12° 30’, read 12degrees, 30 minutes” (Random House).USGS quadrangle maps are common inboth 15 and 7.5 minute sizes. For ex-ample, the 7.5 minute map for CrowButte, Nebraska covers from 103° 15' to103° 22' 30" west, and 42° 37' 30" to 42°45' north. (See also: arcsecond, degree.)

MIPS: Map and Image Processing Systemfrom MicroImages, Inc. First marketedfor DOS computers in 1986. (See also:TNTmips.)

miter: one of the joining methods for lineand polygon segments when creating off-sets for vector elements in the SpatialData Editor. The Miter option creates asingle vertex where the segments meet atan angle.

mnemonic: A single keyboard character as-sociated with a labeled component (suchas a push button or menu selection). Themnemonic is underlined in the label, or ifthe mnemonic is not contained in thelabel, it can follow the label in parenthe-ses. The underscore in the menu selec-tion “View”, for example, indicates thatthe letter “V” is the mnemonic for thatselection, and that pressing the “V” keyon the keyboard will activate the Viewselection. (See also: accelerator.)

model area: The area of overlap in a pair ofstereo images that is selected for creationof a DEM.

MODIS: Moderate Resolution ImagingSpectroradiometer that collects multi-spectral images aboard NASA’s Terra(EOS AM) and Aqua (EOS PM) satellites.These satellites view the entire earth’ssurface every 1 to 2 days with the abilityto directly broadcast in real time its rawdata to appropriately equipped ground sta-tions.

monochrome image: An image displayedin a single color or shades of a single color.

morphological analysis: A process that al-ters or extracts shapes within an image.The morphological functions provided in


TNTmips are dilation, erosion, opening,closing, clump, and sieve.

mosaic: A large image assembled from seg-ments. Each segment may come from adifferent source and have a different cellsize and angle of orientation, but all thesegments must be geometrically rectifiedand calibrated to a common coordinateframework. The mosaic process rotatesand re-scales each piece and creates asingle combined object. If all segmentsare georeferenced to the same map pro-jection, they can be automaticallymosaicked based upon their geographiccalibration without additional adjustments.Recognized verbal forms of mosaic aremosaic, mosaicked and mosaicking.

MOSS: Map Overlay and Statistical System.A pioneer vector-based geographic infor-mation system (GIS) developed and stillwidely used by groups in the USDI, espe-cially the USF&WS and BLM. MOSS vec-tor data files contain strings of coordi-nate pairs which describe closed polygo-nal areas, lines, and single point features.Common boundaries between adjacentpolygons are repeated twice in this datastructure, once with each polygon. Muchgeographic data is available in this for-mat, especially that portion of the NWIwetland maps which have been digitized.

motherboard: The main circuit board in amicrocomputer. The motherboard nor-mally contains the main processor, logicchips, memory, and expansion slots foroptional circuit cards.

mouse: A computer graphics pointing de-vice. As you move a mouse across thedesktop, the mouse cursor moves acrossthe image display.

mouse cursor: Shows the position of mouseactivity or focus on the screen. The mousecursor changes shapes to show the func-tion currently assigned to the mouse. Forexample, an arrow pointer indicates thatthe mouse may be used for selection. Anhourglass or clock shape shows that themouse is inactive during a processing ac-tivity.

mouseover highlight: A color or otherchange to identify the element the mouseis paused over.

mouse pointer: See: mouse cursor

MRI: Magnetic Resonance Imaging. A tech-nique used in medicine to collect com-puter images of internal organs and sys-tems for examination and evaluation. Adevice used in medicine.

ms (millisecond): One thousandth of asecond. A measure of average disk accesstime (the time it takes the drive to posi-tion the read/write head over the re-quested track).

MSS: Multi-Spectral Scanner. A sensing de-vice on the Landsat satellite that col-lects simultaneous images over multipleranges of the spectrum.

multi-byte strings: Text in some charac-ter encoding schemes exceeds the 256-character limitation of single byte en-coding. In multi-byte systems, charac-ters are allotted 2 or 4 bytes each.

multi-frame capture: Capture of two ormore frames in a video.

multilingual application: A computerprogram that allows the user to mix mul-tiple languages and character sets is saidto be multilingual such as a word proces-sor that allows side-by-side columns ofEnglish and Japanese, or even mixtureof Latin characters within a longer Japa-nese text. Multilingualization is morecomplex than internationalization,which limits the program to one locallanguage at a time. TNTmips offersmultilingual support, paticularly withannotation tools for map and poster lay-out which allow mixing fonts of differ-ent character sets. Thus for example, itis possible to create a map that has bothThai and English annotations.

multiple raster set: A set of coextensiveraster objects displayed in unison. Whenthe multiple raster display mode is RGB,HIS, or HBS, three objects are includedin the set. When the multiple raster dis-play mode is RGBI or RGBB, four ob-jects are included. One object in the set isassigned to each display component.

multisensor images: Coregistered imageswith the same cell size collected by dif-ferent sensing devices. For example, a10-meter SPOT panchromatic image canbe coregistered with a resampled LandsatTM image so that their cells correctlymatch. This combination is called a


multisensor image.

multispectral images: Images opticallyacquired in more than one spectral orwavelength interval. Each individualimage is usually of the same physical areaand scale but of a different spectral band.The MSS and TM sensors aboard theLandsat satellite both collect simultaneousmultispectral images. The TM sensorscans and stores seven individual imagesin spectral bands ranging from the bluewavelengths up to those in the thermalinfrared.

multitemporal images: Coregistered im-ages collected at different times by thesame device. For example, airvideo im-ages collected one year apart, digitized,and warped to the same geometry arecalled multitemporal images and can beanalyzed to map the changes betweenthe dates.

multivariable images: An image storedon more than one independent,coregistered raster. For example, a videoframe-grabbed image stored as indepen-dent red, green, and blue rasters is a mul-tivariable image. So too is anymultitemporal, multispectral, ormultisensor image.

multivolume project file: A project filethat is spread over more than one mediaunit by linking to objects on other de-vices.

— N —nadir: The point on the ground vertically

beneath the imaging sensor. That is, ifyou imagine a straight line drawn from asensor to the center of the earth, thenadir is point where that line intersectsthe surface of the Earth. For radar imag-ing, the nadir corresponds to the begin-ning of the near range.

NAPP airphotos: National Aerial Photog-raphy Program airphotos. USGS CIR highaltitude airphotos. The NAPP series re-places the NHAP series. (See also:NHAP.)

NASA: National Aeronautics and Space Ad-

ministration.

navigation: Moving a selection highlight orlocation cursor with a mouse or keyboardthrough the levels of a menu and windowsystem.

ND, ND6 and ND7: Normalized Difference.Vegetation index computations developedfor use with Landsat MSS. These vegeta-tion indices are now commonly used withany image that has the required spectralbands. The bands required are approxi-mately equivalent to the red and thephoto-infrared spectral bands measuredby color-infrared film. The ND6 indexused MSS band 6, and ND7 uses band 7.Since these two Landsat MSS infraredbands are so highly correlated, similar re-sults are possible using either of the com-putations or with any images that havean equivalent photo-infrared spectralband. Good color-infrared image sourcesfor processing into an ND or green biom-ass raster include Landsat MSS and TM,SPOT CIR, 35mm CIR film, 9" CIR film,and CIR video.

near range: That portion of a syntheticaperture radar (SAR) image that is near-est the aircraft flight path.

nearest neighbor sampling/interpola-tion: Resampling a source raster to yielda new raster with a different cell size, ras-ter orientation, and/or internal geometryby computing the distance between thecenter of each cell in the output rasterand the 4 nearest cells in the input raster.The data value for the closest input cell isassigned without alteration to be the datavalue of the output cell. Therefore, theinput value of one input cell may be as-signed to more than one output cell. Italso means that some input cells may notbe transferred at all to the output raster.These undersampling and oversamplingsituations occur when the cell sizes of theinput and output raster are different.

For example, a resampled output rasterwhich is coparallel to the input raster butwhich has cells half as big, will repeat theinput values in a 2 x 2 cell pattern. How-ever, since nearest neighbor resamplingdoes not mathematically compute the newcell’s value, it is the only suitable choicefor rasters that are not mathematically


continuous such as land cover maps. Withsuch maps, mathematical resampling (likebilinear, or cubic convolution) is totallyincorrect since mean values cannot becomputed.

neatline: A cartographic term that meansthe border drawn around the perimeter ofan object.

nested folders: A set of folders within eachother.

Network Analysis: A process that deter-mines the optimal path between twopoints with any number of stops and routecontrol parameters taken into consider-ation (route mode). You can also locatecenters (points) and identify the linearcomponents of the network that shouldfeed that center or that the center shouldservice (allocate mode). Both modes usethe characteristics of the lines and nodesin the network.

NGA: National Geospatial-IntelligenceAgency (formerly NIMA).

NHAP: National High Altitude Photographyprogram. NHAP was coordinated by USGSand operated from 1980-1989 to providea publicly available collection of black andwhite and CIR airphotos covering theconterminous United States. The pro-gram was renamed NAPP in 1987.

NIMA: National Imagery and MappingAgency (formerly DMA, now NGA).

nibble: A data element made up of 4-bits andhaving 16 possible values. Nibbles arestored two to a byte.

NOAA: National Oceanographic and Atmo-spheric Administration.

node element: A vector element requiredfor topology that has no attributes ex-cept position; nodes occur at the ends ofall lines and at all line intersections if thevector object has polygonal topology.

nominal image map: A preliminary mapform that approximates an image mapand that can usually be prepared using fullyautomated procedures. For example,TNTmips can automatically extract a 7.5'nominal image map from Landsat or SPOTsatellite images using the positional andangular properties provided with the im-ages. However, to convert it to an accu-rate image map, the user must introduce

ground control points.

A topographic map that has been scanned(but not yet calibrated) is another ex-ample of a nominal image map. Simi-larly, using TNTmips to mosaic airslidesor airvideo images that cover the area ofa 7.5' map provides a nominal image map.(By contrast, rectifying and assemblingthese source images yields an image map,since that process used ground controlpoints in some map coordinates.) (Seealso: image map.)

non-interlaced video: Video signal for-mats used in some display boards andmonitors. A non-interlaced video dis-play board refreshes the whole displayevery 1/60 of a second. It does notintersplice fields but paints each succes-sive line from top to bottom of thescreen.

normalized contrast: See: contrast.

Normalized Difference: See: ND

normalized histogram: A histogram whosedistribution has been adjusted so as tohave as close to a normalized (bell-shaped) distribution as possible. The datavalue that occurs most frequently will benear the center of the histogram.Multimodal histograms are those whichhave two or more significant peaks intheir distribution and cannot usually besatisfactorily normalized.

northing: A rectangular (x,y) coordinatemeasurement of distance north from aneast-west reference line, usually the equa-tor or other parallel used as the axis oforigin for a map zone or projection. Falsenorthing is an adjustment constant addedto coordinate values to eliminate nega-tive numbers.

NRCS: National Resources ConservationService. A service of the United StatesDepartment of Agriculture to provideleadership in a partnership effort to helppeople conserve, maintain, and improveour natural resources and environment.Formerly SCS.

NTSC video: National Television SystemCommittee video. The standard formatused by all American home video equip-ment (like VCR recorders and televisionsets). All the necessary color informa-


tion is encoded in a single interlaced sig-nal which is often called composite colorvideo.

null value: The absence of a value in a ras-ter object. Null values often occur whena raster is extracted or resampled suchthat the minimum bounding rectangle isnot coincident with the raster edges. Nullvalues may also occur within the image.Null is not the same as zero.

number of weighted runs: A type of in-formation provided with a spectrum in aHyperspectral Analysis spectral library.Each spectrum in the library is generatedin a laboratory and is actually the resultof multiple runs. The number of labora-tory runs is reported as the number ofweighted runs.

NWI: National Wetlands Inventory con-ducted by the USF&WS.

— O —object: An integrated, organized unit of data

stored either in a TNTmips project fileor in an external, but attached file. Theseinclude raster, vector, database, and textobject types.

OCR: Optical Character Recognition.

ODBC: Open Database Connectivity is usedto communicate with database manage-ment systems.

OGC: Open GIS Consortium.

on-the-fly labels: Labels that are not storedas elements in a vector object but aregenerated during the display process us-ing specified parameters.

opaque color: When a new color featurecompletely masks out an earlier featurein an image, the new feature is composedof opaque color. For example, a poly-gon can be overlaid or drawn in opaquecolor upon an image so as to completelyobliterate the original features in thatportion of the image.

open reel tape: (historical term) Medicalimages and satellite images from main-frame and minicomputers were oncecommonly distributed on 12-inch reels

of magnetic tape in standard format.

operand: A parameter that designates a ras-ter object’s identification and location ina raster algebra expression.

operator: The function in a raster algebraexpression that describes action upon araster object or the process by which ras-ter objects, or operands, are to be com-bined.

optical disk: (historical term) A mediumfor computer file storage consisting ofremovable optical disk cartridges. Eachside of a two-sided optical disk typicallyholds from 300 to 500 megabytes of data.These disks havbe been supplanted by CDsand DVDs.

optimization: The process by which TNT-mips assigns display colors to the rasterobject cell values for display of multipleraster objects for 8-bit (256-color) dis-play modes. After TNTmips condensesthe values, 4096 possible colors remain.Of the 256 colors that can be displayedon an 8-bit display board, there is a stan-dard set of 64 colors assigned to all rasterobjects, which are always “known” andavailable for annotation and vector over-lays. The remaining 192 colors assignedto the color map, are those that occurmost frequently in the RGB set of objectsbeing displayed. The colors in this RGBset that are not found in the 256-membercolor map are assigned to be displayed astheir closest match in the color map. Thisprocess produces a very good naturalcolor image on an 8-bit display board.

option: An item on a menu.

option button: A type of button that opensan option menu. When a new selection ischosen from the option menu, the newselection is displayed as the button label.

Oracle Spatial: A relational database man-agement system from Oracle Corpora-tion that includes spatial elements, whichTNTmips can directly display as a shapeobject or import to a vector object.

orthoimage: An airphoto or satellite imagethat has been processed to remove per-spective distortions and so to have theproperties of an orthographic projection.Distortions of tilt and relief are removed


so that all features in an orthoimage arein their true orthographic positions.

orthophoto: An airphoto that has beenscanned, rectified, and reconstructed soas to represent its features in a map pro-jection or at least in a flat rectangularform without the usual distortions of ge-ometry and perspective. Usuallyorthophotos are prepared from very highresolution stereo pairs.

outliers: Geodata points that lie far fromthe regression line. Outliers can be legiti-mate geodata points that show the ex-treme variability of the geodata or theycan represent errors, such as incorrectlyrecorded geodata, an instrument malfunc-tion, and so forth. Researchers drop out-liers from statistical analyses when theoutliers are shown to be errors becausethe outliers can skew statistical analyses.

outline font: A font in which each characteris described by a set of lines or polygonsrather than by individual pixels. Thus,outline fonts can be rescaled to any sizeand displayed at any resolution with nodegradation of appearance. (See also:bitmapped font.)

outline highlight or location box: Showswhich menu selection or button in a win-dow is the object of keyboard or mousefocus.

out-of-gamut colors: Colors that are notconvertible to the “gamut” of colorsdisplayable on a color monitor. Out-of-gamut colors may be encountered whenPhotoCD imagery is imported into TNT-mips.

overlay: (vector, CAD, shape, TIN) A largelytransparent layer placed on an underlyingimage. The overlay is where symbols,annotations, or image traces can be cre-ated or displayed without changing theunderlying image. A TNTmips symboloverlay is a vector object with symbolshapes assigned to its nodes so that thesymbols line up with features of intereston the underlying image. For example, aduck symbol might overlay a duck habitatfeature and be linked to a database recordwith site specifics.

overshoot: A line that extends beyond an in-tersecting line where it was intended toend.

OWS: Open GIS Consortium (OGC) WebServices.

— P —page layout: The process of selecting, siz-

ing, and positioning multiple items tocompose a page for printing. Also theresult of this process.

PAL: Phase Alternating Line. A video stan-dard generally used by the rest of theworld outside the United States andCanada that is not compatible withNTSC.

pan: To move over an area of an image thatis larger than the on-screen viewing area.

panchromatic image: An image collectedin the broad visual wavelength range butrendered in black and white. The termhas historically referred to a black andwhite photograph of a color scene. Sincethe SPOT satellite 10-meter images arecollected over this broad visual spectralband and are usually rendered in blackand white, these images are called pan-chromatic.

pane: A resizable subarea of a window con-taining related options or componentsand set off from other areas of the win-dow by separators. The Tab key movesthe location box from pane to pane.The arrow keys move the location boxfrom component to component withinone pane.

panel: A work area in a window composedof basic controls such as an array of but-tons and sliders.

panoramic: A type of view in which theviewer has an unobstructed view of anextensive area.

parallax: The apparent change in relativepositions of stationary objects caused bya change in viewing position. Parallaxdisplacements in overlapping imagesonly occur parallel to the line of flight.

parallel: Two or more lines that are sepa-rated by the same distance at all points.Also a horizontal circle on the globe at aconstant latitude.


parallelepiped classifier or decisionrule: A simple form of automated com-puter interpretation slightly more com-plex than boxcar interpretation. For par-allelepiped classification, the boundariesbetween classes need not be rectangularor parallel to the axes. A parallelepipedarea representing the location of eachmaterial sought is prism-shaped in the 2-, 3-, or n-dimensional distribution of theavailable multivariable images. (See also:boxcar classifier)

parallel port or parallel interface: Aphysical connection between a computerand a peripheral device, such as a printer.A parallel port uses a connection thathas more than eight wires. Eight of thewires simultaneously convey the eightbits in a byte of data, while the remain-ing lines control status information suchas “send me more” and “stop sending.”Standard parallel ports in Windows arenamed LPT1, LPT2, and LPT3.

parallel projection: A visualization of athree-dimensional object as a wireframeobject in which parallel lines remain par-allel throughout the view.

parallels: Circles on the earth’s surface, orlines on a map that are perpendicular tothe axis of the earth, and mark latitudenorth or south of the Equator.

parent object: An independent prime ob-ject in a project file related to some otherprime object below it in the project filehierarchy. An object linked by Hyper-Index to some other objects is the par-ent of those objects (referred to as itsdaughter objects). (See also: daughterobject, HyperIndex, index area, link,stack.)

Paris classification: An unsupervised clas-sification or clustering process developedby Dr. Jack Paris and documented in: JackF. Paris and Helenann H. Kwong (1988)Photogrammetric Engineering and Re-mote Sensing 54(8):1187–1193. Char-acterization of Vegetation with CombinedThematic Mapper (TM) and Shuttle Im-aging Radar (SIR-B) Image Data.

path: A description of the hierarchical chainof directories that define the logical lo-cation of a file. A path specifies a loca-tion using a string of characters signify-

ing directories, seperated by a delimitingcharacter, most commonly the slash "/"(as in Unix/Linux) or backslash character"\" (as in Windows).

PC ARC/INFO: A vector-based GeographicInformation System (GIS) developed andmarketed by ESRI, Inc.

PC ARC/INFO coverage file: pcARC/INFO’s legacy data directory for the 13different file types used to store theequivalent of a single TNTmips vectorobject.

PCIPS: (historical term) A raster-based mi-crocomputer image processing system de-veloped in the early 1990's and distrib-uted by IBM. PCIPS was a menu-ori-ented entry-level system for systems withCGA and EGA video boards.

PC-8: An 8-bit (256-character) IBM superset of the 7-bit ASCII character encodingscheme that includes various symbols plusLatin characters with diacritics. Printersand other output devices do not deal withthe upper 128 characters in a standardfashion. Thus, what looks like an “i”with two dots instead of one (ï, PC-8 char-acter 139) on the screen may print assomething completely different. PC-8makes different assignments for codes128-255 than does Latin-1, and thus isnot a proper subset of Unicode or ISO10646.

pen: One type of pointing device (some-times called a “stylus”) used with an X-Ydigitizing tablet. It has a pencil-like feelwhich makes it ideal for free-hand draw-ing. (See also: pointing device, puck.)

pen plotter: An output device for line draw-ings that mechanically moves an ink penover the drawing surface.

perceptual rendering: A rendering intentthat is best for photographic images whenthe destination gamut is narrower thanthe source gamut. Perceptual renderingcompresses the entire source gamut whilepreserving the relationship between col-ors.

peripheral device: A hardware device that isnot part of the computer, such as aprinter, scanner, or digitizer.

perspective projection: A visualization ofa three dimensional object in which par-


allel lines converge towards a vanishingpoint.

petabyte, Pbyte, or PB: A unit of computermeasurement for 250 (approximately)1,000,000,000,000,000 bytes,1,000,000,000,000 kilobytes,1,000,000,000 megabytes, 1,000,000gigabytes, or 1000 terabytes. (See also:bit, byte, exabyte, gigabyte, kilobyte,megabyte, terabyte.) Also petabyte.

photogrammetry: Obtaining precise mea-surements from images.

photointerpretation: Analyzing, measur-ing, and categorizing chosen features fromairphotos.

physiographic: Describing the characteris-tics of a site’s physical geography.

picklist: A defined set of allowable attributesfor a particular feature type that is pro-vided as a list.

pictograph: A pictorial sign or symbol, forinstance, representing a person with astick figure.

picture element or pixel: “The smallestelement of an image that can be individu-ally processed in a video display system”(Random House).

piecewise affine: A transformation methodfor rectifying images that assumes eachcontrol point is correctly positioned andthen uses these points in groups of threeto transform an image by transformingeach triangular portion of the total im-age.

Pinyin: (literally, “spell sounds”) The pho-netic alphabet based on Latin lettersadopted in the People’s Republic of Chinain 1958 based on the Beijing/Mandarinversion of spoken Chinese.

pixel or picture element: “The smallestelement of an image that can be individu-ally processed in a video display system”(Random House). The text and imageson a computer display are created by com-binations of individual dots (pixels). Dif-ferent display hardware allows for moreor fewer pixels on the screen, determin-ing the display resolution that is possible.The more rows and columns of pixels,the finer the image detail that can be re-solved.

pixel depth or color depth: The number of

data bits each pixel represents. In 8-bitcontexts, the pixel depth is 8, and eachdisplay pixel can be one of 256 possiblecolors or shades of gray. With a 24-bitraster (or with three coregistered 8-bitrasters) the pixel depth is 24, and16,777,216 colors are possible.

planimeter: “An instrument for measur-ing mechanically the area of plane fig-ures” (Random House). TNTmips con-tains the electronic equivalent of aplanimeter; you use the mouse to drawaround a shape on the display screen andTNTmips calculates and displays its area.

planimetric map: A map designed to por-tray the horizontal positions of features;vertical information is specifically ig-nored.

PNG: Portable Network Graphics. An imageformat for lossless compression devel-oped as a patent-free replacement forGIF.

point element: A single point defined by aset of coordinates in space, and one ofthe types of elements in a TNTmips vec-tor object.

Vector elements may cross-index theirclass attribute to a list containing theelement drawing style, which may includepolygon fill pattern, point symbol, linewidth or symbol/point size, RGB color,RGB label color, RGB fill color, label fontnumber, label font size, label font zoomfactor, label font style, and label rota-tion angle.

pointing device: A hand-held drawing toolused with an X-Y digitizing tablet to reg-ister coordinate data. This can be eithera mouse-like puck or a pen. (See also:pen, puck)

point size: The vertical size of a text fontis expressed in points. There are 72 pointsin an inch, so a 12-point font would be12/72, or 1/6 of an inch tall, while a 36-point font would be 36/72, or 1/2 inchtall. Of course the heights of differentletters vary (‘L’ is taller than ‘e’). Thepoint size refers to the distance betweenthe highest ascender in a font’s charac-ter encoding scheme (the part above theline in a letter like ‘l’ or ‘b’), and thelowest descender in the set (the part be-low the line in a letter like ‘g’ or ‘y’).


(See also: bitmapped font, outline font)

polygon element: A type of element in aTNTmips vector object. A polygon isdefined by a list of line elements storedelsewhere, which can be retrieved and as-sembled to form a closed shape.

Vector elements may cross-index theirclass attribute to a list containing theelement drawing style, which may includepolygon fill pattern, point symbol, linewidth or symbol/point size, RGB color,RGB label color, RGB fill color, label fontnumber, label font size, label font zoomfactor, label font style, and label rota-tion angle.

popup menu: A hidden menu that opens bypressing a mouse button, usually in somespecific area of the display, such as overthe background. The system gives novisual clues that indicate the presence ofa popup menu.

port: A physical and logical interface for aconnection device between a computerand another component (such as a printeror a modem).

PostScript®: A standard page-descriptionlanguage for sending image informationfrom a computer to a printer. PostScriptwas created by Adobe Systems, Inc., andis used in many computerized phototype-setting systems.

pour point: (watershed analysis) The lowpoint on the boundary ridge between twoneighboring watersheds. It is the pointthrough which water from one watershedwould begin spilling over into its neigh-bor if it were completely filled.

precomputed: An object saved in the for-mat in which it will be viewed, such as atileset.

prerendered: An object saved in the for-mat in which it will be viewed, such as atileset.

primary key: An important field within adatabase record. Each table may haveonly one primary key. Designation as aprimary key requires that all records havean entry for the field and that eachrecord’s entry for this field be unique.(See also: database object, field, foreignkey, record, table.)

primary object: One of the basic types of

project file objects with which a TNT-mips user works: raster, vector, CAD ordatabase. (See also: project file.)

Prime Meridian: The meridian on theearth’s surface from which longitude ismeasured; generally the meridian ofGreenwich, England. This meridian di-vides the earth into eastern and westernhemispheres.

principal components: A statistical tech-nique for reducing an image’s dimension-ality. Principal components choosesuncorrelated linear combinations of a setof rasters in such a way that each succes-sively extracted linear combination,called a principal component, has asmaller variance. If the rasters have sig-nificant linear intercorrelations, the firstfew components will account for a largepart of the total variance.

principal point: (photogrammetry) Thefoot of the perpendicular from the inte-rior perspective center to the plane of aphotograph. The principal point is physi-cally located at the center of the photo-graph by intersecting the lines that con-nect opposite fiducial marks.

printel: The smallest element a printer canprint, or a single “dot” on a printed page.The printed equivalent of a pixel.

print-file: A file created from a TNT pagelayout that includes all information nec-essary for a designated printer to printthe file. Unlike print-rasters, print-filesare not viewable in the TNT diaplay pro-cess. Print-files created using the TNTprint drivers are actually a pair of files:one with the name you assign and a .prfextension (small file), the other with thename you assign and a .p1 extension (largefile). If the layout is printed with TNTdrivers and covers multiple pages, therewill also be a *.p2 file and so on. There isjust one *.prf file regardless of the num-ber of pages. Print-files created using theWindows printer driver have a .prn ex-tension and there is only one print-fileregardless of the number of pages. Print-files are supported on the Macintosh butonly using TNT printer drivers.

You may want to create print-files whenyou will be printing at a later time par-ticularly if the printer is attached to a


machine that does not have TNT installed.Print-files can be printed from withinTNT (Main/Print From/Print-File) or bycopying the file to the port for the printerdesignated when the print-file was cre-ated.

print-raster object: A raster that contains adot-by-dot representation of a color printpage that is viewable and can be manipu-lated in the TNT products like any otherraster object. Print rasters are either 4-bit (dithered) or 24-bit (undithered). Eachcell in a dithered print-raster object is anibble (1/2 a byte or 4 bits), which canspecify 16 data levels. The 8 values cur-rently used define one color compositedot on the printed page. Printers createeach color composite dot from dots ofcyan, magenta, and yellow (and possiblyblack) or red, green, and blue (and possi-bly black). Combinations of the threecolors together with black and white arespecified by each nibble’s 8 possible datalevels.

You may want to create print rasters whenyou are planning additional modificationsof the raster or you want to be able toview it before printing. You specify thedesired printer at the time you print aprint raster (Main/Print From/Print-Ras-ter).

probability: “A statistical description of therelative possibility that an event will oc-cur. Probability is expressed as a ratio ofthe number of actual occurrences to thetotal number of possible occurrences”(Random House).

processing mask: You define a processingmask in the Feature Map process to iden-tify which portions of an image to in-clude in the Feature Mapping analysis, andwhich to exclude. The processing maskcan be as complex as you like. For in-stance, you can outline an irregular areain an airphoto to include, but exclude lakesurfaces in that area, and yet include is-lands in the lakes. (See also: mask)

processing raster(s): TNTmips image in-terpretation processes can use either asingle raster object or a set of raster ob-jects. That is, you can use one rasterobject for the display, and another rasterobject or set of raster objects for process-ing. In the simplest case, you use the same

raster object for both the processing ras-ter object and your reference on the dis-play. In a more complex case, you useone raster object for the display image,and a whole set of raster objects for pro-cessing. (The processing set may includethe display raster.) For instance, you coulduse a raster object with a composite natu-ral-color image of the study site for thedisplay, while using the seven raster ob-jects containing the spectral bands of theLandsat Thematic Mapper data for pro-cessing. (See also: reference image.)

profile: XY plot of values, such as eleva-tion / distance.

profile format files: These files tell print-ers, monitors, and other hardware deviceshow to provide sRGB colors. Profile for-mat files go by two names: ICC on theMacintosh and ICM on WIndows plat-forms.

Project File: TNTmips’ integrated datastructure for large, user-defined collec-tions of objects and subobjects. Thissingle structure allows for the creationand manipulation of rasters, vectors, da-tabase files, and text files. A Project Fileis a single, conventional Windows,Macintosh, Linux, or Unix file that maybe as large as 4 gigabytes for Windows 98and XP, and up to 16 terabytes for neweroperating systems.

projection or map projection: “A devicefor representing all or part of a roundedsurface on a flat sheet. Since this cannotbe done without distortion, the cartogra-pher must choose the map characteristic[area, shape, scale, direction] which is tobe shown accurately at the expense ofothers.” Map Projections Used by the U.S. Geological Survey, Geological SurveyBulletin 1532, Second Edition, U. S. Gov-ernment Printing Office, Washington, D.C. , 1982, p. 5.

Every process that establishes or trans-lates map projections offers the samestandard selection list of projections.The practical choice of map projectionsfor ungeoreferenced project materials isnormally determined by the kind of pro-jection used by those project materialsthat are calibrated to a projection. Forexample, if you have a scanned USGS


topo map in the polyconic projection,you may decide to calibrate satellite im-ages and vector overlays (or translateexisting calibration) to the same projec-tion. (See also: ellipsoid.)

prompt: A screen display, such as a blinkingunderline or a question mark that may beaccompanied by a beep, indicating theneed for a keyboard response by the user.

prototype or training set: Sample cells inan image known to represent a featuretype or ground cover of interest that youdefine from ground visitation, detailedairphoto interpretation, or other per-sonal experience.

prototype cell or training cell: Onesample cell that you select as belongingto a feature type. May also be called a“training cell.”

proximity map: A map that shows the dis-tance from selected features by gradientshades of color. TNTmips can produce a“distance raster” that shows distancesfrom vector elements. Cells that are closeto the vector elements have low values,and cells that are farther away havehigher values. When displayed such ras-ter objects show greater distances withgreater display intensities.

pseudo-color image: A color image thatdoes not directly render the colors of theoriginal image from individual red, green,and blue color values. A pseudo-colorimage could result from such processesas assigning colors to the gray levels in agrayscale image or assigning colors to acluster map. A color map pairs a displaycolor with each possible cell value in apseudo-color image. (See also: compos-ite color raster object.)

puck: One type of pointing device (some-times called a “cursor”) used with an X-Y digitizing tablet. It has a crosshairslens which allows for precise placementof digitized points. (See also: pen, point-ing device)

pulldown menu: A menu that opens undera menu title on the menu bar.

push button: Button that starts the opera-tion indicated by the button’s label. Apush button cannot be left “on” or “off.”

(See also: toggle button.)

— Q —quad, quadrangle, map quad or map quad-

rangle: The geographic area covered bya map. One kind of map quadrangle is the7.5' x 7.5' area that is covered by a stan-dard USGS 7.5' topographic map. Refer-ring to a 7.5' map quadrangle does notimply the presence of an actual papermap. The term may simply designatethe area covered by electronically storedmaterials.

quadkey: Short for quadtree key. This termis used by Microsoft in connection withBing Map tilesets to index the positionsof individual tiles.

Quadratic BSpline: A curved smoothingthat can be applied to a line. A BSpline iscalculated by a polynomial equation. Dif-ferent types of BSplines, such as CubicBSpline and Quadratic BSpline, can be cal-culated from different types of polyno-mial equations.

quadtree: A method of representing two-di-mensional space by recursively breakinga square of space into four squares half itssize, which are made its children in a treedata structure.

quantization: Dividing a continuous rangeinto a finite set of discrete values calledquantization levels. If too few quantiza-tion levels are used, false contours mayappear in an image. Quantization levelsare often referred to as “gray levels,” butthe concept can also apply to color im-ages.

query: A query, or database query, is a set ofinstructions defining attribute criteria thatare used to select records from a database.The specific spatial elements (such aslines or polygons) to which those recordsare attached are then automatically se-lected for the current process.


— R —radar image: An image composed of many

pixels, each of which represents the radarback scatter for that area on the ground.Darker areas have less back scatter thanbrighter areas. Bright features in an im-age are those that return a large fractionof the radar energy to the sensor, whiledark features reflect little or no energy tothe sensor.

radiance: “Radiant brightness or light: theradiance of the tropical sun” (RandomHouse).

radio button: A type of toggle button in agroup of toggle buttons where only oneof the toggle buttons can be on at a time.A radio button is preceded by a graphicindicator of the state of the button.

RAM: Random Access Memory. Read/writememory for programs and data that thecomputer uses as a general work area. Themore RAM in a computer, the more gen-eral work space it has and the larger theprojects it can handle.

RAM disk: RAM that is reconfigured to worklike a very high speed disk drive.

The system uses a RAM disk just as it doesany other disk drive. But since a RAMdisk is not a true magnetic storage device,its contents are lost when the computer isrebooted. Any permanent files must becopied from a RAM disk to permanentstorage before turning off or rebootingthe computer.

range extraction: A method of convertinga grayscale raster object into a binary ver-sion. In range extraction, two boundaryvalues are selected to bracket the desiredrange of grayscale values. Everythingabove and below the boundary values isset to 0 (black), while everything betweenthe boundary values is set to 1 (white).

raster or raster object: A single, related,two dimensionally grouped set of num-bers of a single data type. Each numberrepresents the value of some parameter.Its position in the group represents itsrelative position to the other values. A

raster object is a raster that is stored inan RVC project file.

raster algebra: Manipulations and func-tions that operate on raster objects cellby cell. Any raster object can be used asa variable, or operand, in a raster alge-braic expression. You just set up a com-bination of operands in an equation andthen assign a raster object to each oper-and. The result of the operation is storedin a new raster object.

raster cell: One value in a raster. If theraster contains geodata, such as an imageor elevation surface, each raster cell cor-responds to one specific area on theground. A raster cell value may be theelevation above sea level at one positionin a survey site or the intensity of redradiation for a pixel in a video image.For convenience, a raster cell is usuallythought of as square or rectangular, al-though many image collection devicesactually measure circular or elliptical ar-eas.

raster space: The area of a raster objectstored in an RVC Project File. This areacan be very large, up to 2,000,000,000by 2,000,000,000 cells.

RDBMS: A Relational Database ManagementSystem has data organized in tables thatcan be related to each other using pri-mary/foreign keys.

record: A database in TNTmips is organizedinto tables, which contain records. Eachrecord supplies information gathered foran individual example. Records containone or more fields related to the topic ofthe table in which they are found. Forinstance, the Crow Butte soil polygondatabase has a table of crop potentials,and there is a record for each soil type.(See also: database, field, table.)

rectification: Removing geometric distor-tion from a raster or a vector object.Rectification is usually achieved by align-ing raster features or vector coordinatepositions with features in a base map orother coordinate reference framework.Rectification may be used to bring sev-eral distorted image segments into a com-mon framework so they can be combinedinto a larger image.

reference image: An image on the display


used for visual reference that is gener-ated by (or otherwise corresponds to) araster object or set of raster objects. Forinstance, TNTmips image interpretationprocesses can use either a single rasterobject or a set of raster objects. That is,you can use one raster object for the dis-play, and another raster object or set ofraster objects for processing. In thesimplest case, you use the same rasterobject for both the processing raster ob-ject and your reference on the display.In a more complex case, you use oneraster object for the display image, and awhole set of raster objects for process-ing. (The processing set may include thedisplay raster.) For instance, you coulduse a raster object with a composite natu-ral-color image of the study site for thedisplay, while using the seven raster ob-jects containing the spectral bands of theLandsat Thematic Mapper data for pro-cessing. (See also: processing rasters.)

region: A simple object used to define a com-plex geographic area of interest. Re-gions have rudimentary topology in thatalternating nested polygons are insidethen outside the region. Regions pro-vide sophisticated and powerful selectioncapabilities for analytical tasks.

region of interest: (Feature Mapping) De-fines the area of the input raster objectsto be considered for all subsequent pro-cessing while that region is selected. Aselected region of interest affects the cat-egories that can be defined, limits thearea in which cells that satisfy the deci-sion rule are searched for, and definesthe region of the feature mapped rasterfor which measurements are tabulated inFeature Mapping’s statistical report. Fea-ture marking is also limited to the regionof interest. (See: categories, feature map-ping.)

registration: Geometrically aligning setsof image data such that correspondingfeatures are coincident. (See also:coregistration.)

regression line: A line that best describesall the data points using a particularmethod of error estimation, such as leastsquares.

relative colorimetric rendering: A ren-

dering intent in which an exact colormatch is required in everything but bright-ness, which may be modified so that therange of brightness matches that of thedestination gamut. The source white istransformed into the destination white,and all other colors are shifted accord-ingly.

relief: (as in shaded relief) The variation ina raster object’s values that shows differ-ences between a surface’s higher and lowerparts in elevation and slope.

render: Create an electronic or hardcopyrepresentation, particularly of an outlinefont. When an outline font is rendered,it assumes a fixed size and shear angle onthe screen, raster, or hardcopy to whichit is rendered.

rendering intent: Determination of how tohandle colors that are available in thesource image that are not available forprinting from the following choices: ab-solute colorimetric, relative colorimet-ric, perceptual, and saturation.

reproject: To change an object from one mapprojection to another. In the TNT prod-ucts, reprojection can be done on-the-flyin the Display Spatial Data process, or itcan be used to create a new object withthe desired projection using the resam-pling or warping processes.

resample: To interpolate cell values in araster object and create a raster with largeror smaller cells. TNTmips resamples ras-ters “on-the-fly” to change their scale ororientation for display purposes. Themeans to save raster objects with changedscale, orientation, or geometric propor-tions is also provided. (See also: interpo-lation.)

residual: The difference between a valuecomputed by a model and the value en-tered by a user such as is found in theGeoreference process.

resize: To change the height and/or width ofa window.

resolution: The level of object detail orsharpness determined by how many pic-ture elements compose an area of a dis-play or corresponding raster. Resolutionmay refer to sensors, raster objects, ordisplays. Low resolution display devices


produce images with a grainy visual tex-ture. High resolution displays use suchsmall picture elements that they can pro-duce a near-photographic quality image.(See also: ground resolution.)

resolution: (digitizer) The smallest move-ment that can be detected by the digi-tizer. Resolution is usually expressed ineither measurement units (.001") or dots-per-inch (1000 dpi).

restitution: The determination of the true(map) position of objects or points; theimage appears distorted or displaced onunprocessed aerial photographs. Restitu-tion corrects for displacement resultingfrom both tilt and relief displacement.Restitution in classic photogrammetry iscommonly achieved by analytical meth-ods or through the use of stereoscopicplotting instruments. Theorthorectification processing step inTNTmips applies elevation informationfrom an elevation raster object to an im-age to produce an orthoimage output ras-ter object.

RGB: Red, Green, and Blue. The red-green-blue color model uses position within acube to describe colors. The axes of thecube are the red, green, and blue values.The shades of gray are found along thediagonal from the origin of the cube, wherered, green, and blue values are zero andthe apparent color is black, to the oppo-site corner, which appears white (red,green, and blue values are 100%). RGB isgenerally used in reference to the sepa-rated spectral bands of an image so thatthe red, green, and blue bands taken to-gether create a natural color image. (Seealso: HBS, HIS.)

RGBB: A display method that converts anRGB raster set into an HBS raster set andthen substitutes a fourth coextensive ras-ter object for the brightness componentbefore conversion back to RGB compo-nents for display. The object selected forthe brightness component is generally ofhigher resolution than the objects selectedfor the RGB components and imparts ahigher pseudo-resolution to the displayedimage. (See also: HBS, RGB.)

RGBI: A display method that converts anRGB raster set into an HIS raster set and

then substitutes a fourth coextensive ras-ter object for the intensity componentbefore conversion back to RGB compo-nents for display. The object selected forthe intensity component is generally ofhigher resolution than the objects selectedfor the RGB components and imparts ahigher pseudo-resolution to the displayedimage. (See also: HIS, RGB.)

RGB set: A set of coregistered, coextensiverasters that represent the red, green, andblue bands of an image.

RGB video: A video image composed ofseparate red, green, and blue signals. RGBvideo is a general term that applies todifferent technologies (analog or digital)and standards (like TTL and RS-170).

RMBM: right mouse button menu.

root table: A table at the root of the hierar-chical database tree (left-most side of thetree) in the Database Editor.

root window: The main window of the Xserver in X desktop mode. Each clientprocess runs as a subwindow within theroot window. On Windows systems, youcan choose to display the MicroImagesX Server title bar if desired. Besides iden-tifying the MicroImages X Server, thistitle bar provides access to preferences,the overview window, the X server ver-sion number, and MicroImages’ techni-cal support email address

row: A horizontal list of data values or dis-play cells in a raster object or display.

RPC: Rational Polynomial Coefficient usedfor producing an orthorectified satelliteimage.

RS-170 video: An historical standard forRGB analog video in the USA that gov-erns the form of the RGB color signals.RS-170 video has a 15.7 kHz horizontalscan rate and a 30-cycle per-second framerate. It is not modulated with a carrier asis broadcast video.

rubbersheeting: Any process in which araster is stretched differentially to matcha new set of geometric constraints. Thisshape change could be defined by anyone of many transformations such aschanging a map projection, trilaterationto change the absolute position of cellswithin a raster, fitting a polynomial to a


surface, least squares movement of con-trol cells, and so on.

run-length encoding: A compressionmethod for raster data stored by row withtwo or more adjacent cells being recordedas a single value and its run (number ofcells with that value).

RVC file: Raster/Vector/CAD formattedfile. The extension for the TNTmipsformat for Project Files is .RVC. Thesefiles incorporate the benefits of a 32-bitcompiler. (See also: Project File.)

RVF file: Raster/Vector Format(ted) file.The DOS extension for all MIPS (v3.3and earlier) Project Files was .RVF.

— S —samples: Groups of cells in an image se-

lected to represent one feature type orland cover of interest. You define samplesfrom your knowledge of the site. (Seealso: prototypes, training sets.)

sample set: For unsupervised classificationprocesses, a set of sample cells that isselected from the input raster set andused to automatically define classes. Theselection of the sample set during pro-cessing is controlled by a sampling inter-val (in line and column directions).

sampling: The process of approximatingan image using a subselection of pixels.Sampling is usually done at constant in-tervals though this is not required. Gen-erally, as the number of samples increases,the quality of the image increases. (Seealso: resample.)

SAR: Synthetic Aperture Radar. SAR uses amicrowave instrument that sends pulsedsignals at targets and processes the re-turn signals that it receives. The SARsensor can function day or night and re-gardless of weather conditions. SAR dif-fers from other radar imaging processesbecause it synthesizes a greater antennalength than actually exists. Signals re-ceived and recorded by the radar systemas it moves along its flight path are Dop-pler-shifted. By comparing the Dopplerfrequencies to a reference frequency,

many of the returned echoes are focusedon a single point effectively increasingthe length of the antenna that is imagingon that point. Very precise knowledge ofthe relative motion between the sensorplatform and the imaged objects is re-quired.

sash: A small graphic control component onthe separator between two panes. A sashmoves the separator to change the sizeof the panes. Drag the sash with themouse to make a pane larger or smaller.

saturation: One of the three coordinatesthat the HBS and HIS color domains useto define a display color. Saturation des-ignates how far away a color is from agray or neutral color of equal intensity.(See also: HBS, HIS.)

saturation rendering: A rendering intentin which the original colors are modifiedto exactly fill the destination gamut whilepreserving the saturation of the colorssuch that some parts of the color spaceare expanded and others are compressed.No other rendering method can expand anarrow gamut to be wider.

scalar: An SML variable for numeric values.The SML naming conventions presumeany variable that begins with a lower caseletter is a scalar value or a string.

scale bar: A map component that shows themap scale graphically. Also called a sta-dia bar.

scale-lock: A GeoLock option; adjusting themap scale of one View window in a set ofopen View windows changes to the newmap scale all View windows for which youset up scale-locking.

scale value: A number used as a multiplier totranslate a set of numbers from one rangeof values into another. For example, aset of decimal values that range between0 and 2 could be projected into the nu-meric range of 0 to 100 by multiplyingeach number in the set by a scale value of50.

scanner: A digitizer that produces an image(raster object) from flat input materialsuch as photographs, maps, and drawings.

scatterplot: A graph of point geodata.

script: An uncompiled program written with


SML. A script may define styles, create anew display layer, perform custom pro-cessing, or a define a tool or macro.

scroll: “To move the current text or imageup, down, or across the monitor so thatnew text or image appears on one edge ofthe screen as it disappears from the other”(Random House). Scrolling is controlledin TNTmips with the mouse and the ar-row keys. For example, a list of objectsin a project file which is too long to fit onthe text screen can be scrolled up anddown with the vertical arrow keys.

scroll bar: Indicates position of current viewin relation to the whole, and used to changethe user’s viewpoint. The scroll bar con-sists of a slider, scroll area (“trough”),and scroll arrows.

SCS: Soil Conservation Service. A service ofthe United States Department of Agricul-ture. Now called the NRCS.

SCSI port: Small Computer Systems Inter-face (SCSI is pronounced “skuzzy”). Aphysical connection between a computerand a peripheral device, such as an exter-nal hard drive or optical drive. Now largelysupplanted by USB connectors.

seam: The junction in the area of overlapbetween raster objects combined by tilingor mosaicking in TNTmips.

SECAM: Sequential Couleur à Memoire. Avideo standard used in France and theformer USSR.

sections of land: The U.S. Public Land Sys-tem divided much of the U.S. into squaresections of land with an area of approxi-mately 1 square mile (sides 1 mile long).Since most of this survey was completedin the late 1800s, these sections varygreatly in area and shape. In some areassurvey adjustments have created sectionsas big as 2 square miles. Sections are thebasic unit of land ownership in the centraland western U.S. They are usually boundedby roads that give rise to the checker-board land patterns characteristic of theseareas.

seed point: (watershed analysis) Any speci-fied point in the landscape used to deter-mine the upslope area (basin) that drainsto that point.

segment: A segment is a line or polygon

that forms part or all of a glyph. A glyphmade from polygons will be filled whenprinted but may optionally be displayedin outline form. A glyph made of linesegments rather than polygons is knownas a stroke font. It is faster for the com-puter to draw a stroke font than a fontmade of polygons.

select: To choose objects or element typesfor display or other operations.

select button: The mouse button used tomake a selection. TNTmips assigns theselect function to mouse button one,which is generally the left mouse buttonunless you have reconfigured your mousesetup.

selection box: (more properly called thelocation box) A graphical symbol thatmarks the current location of keyboardfocus for an operation. Moved with Taband arrow keys.

selection highlight: An item displayed inreverse video in a text list, that indicateswhich member of the list is selected. Youcomplete the selection by pressing the<Enter> key (or double clicking with theleft mouse button).

selection query: (in database queries) Aselection query is constructed from oneor more comparison expressions. Onlyif the entire query evaluates to “true”(non-zero) for an element, is the ele-ment included.

selection set: All elements currently se-lected by the Element Selection tool forviewing or editing make up the selectionset. One element in the selection set,generally the last element selected, is theactive element. Attribute assignmentsand editing changes can be applied to justthe active element or to all elements inthe selection set. (See also active ele-ment.)

semivariance: Statistic that compares ad-jacent cells and calculates their related-ness.

semivariogram: Plot of semivariance val-ues.

separator: A dividing line that marks a logi-cal division between areas of a window ormenu.

serial port: A physical connection between


a computer and a peripheral device, suchas a plotter. The eight bits in a byte aretransmitted serially, or end to end,through a single line while the remaininglines contain status information such as“send me more” and “stop sending.”Windows standard serial ports are namedCOM1 and COM2.

serpentine order: A grid cell numberingscheme found in the Polygon Grid analy-sis process. When a user selects the Ser-pentine Order scheme, the sequentialnumbering proceeds from the lower leftcell upward to the top of the first col-umn; numbering then proceeds downwardthrough the second column, and so forth.

shaded relief: See: relief.

shapefile: a popular geospatial vector dataformat developed by ESRI that can beused by a number of different softwareproducts. Shapefiles contain only oneelement type and have only one attributetable, which has an implied one-to-oneattachment type. A shapefile is actuallya collection of same-named files with dif-ferent extensions, some of which are re-quired and some are optional. The filewith the spatial elements has a *.shp ex-tension. The other required files are theindex file (*.shx) and a database file(*.dbf).

shape object: A coordinate data object withno topology used for direct display ofESRI shapefiles and Oracle Spatial lay-ers.

shear: Angular slant given to a vector fontto produce the effect of italics.

shift sequence: A keyboard technique fortext entry in a language that uses morethan one character set, such as Japanesewhich uses a mix of ideographs, Latincharacters, and Japanese phonetic char-acters. The user enters a shift sequenceto switch from one character encodingscheme to another. Electronically, eachcharacter is preceded by a shift sequencebyte that identifies its character set.

slant range: The distance measured alonga line between the radar antenna and eachtarget (that is, each reflecting point inthe illuminated scene). The measure-ment is perpendicular to the line of flight.

slider: A graphic control component thatcontrols the setting of a variable. Movethe slider by dragging it with the mouse tomake its associated value larger or smaller.

sliver polygon: A polygon with a very highperimeter to area ratio or simply verysmall area. Such polygons are oftenformed when vector objects are merged.

slope: A measure of how steeply a surface orline inclines. Slope is computed by divid-ing a line’s vertical rise or fall by the dis-tance the line travels on the surface (the“rise over the run”)—usually expressedas a percent.

smart line following: An interactive pro-cess for converting raster line images toline elements in a vector object. Theuser clicks on a line image, and the pro-cess follows the line, over-tracing a vec-tor line. The process stops at the edge ofthe raster, at the end of the line, or at aspaghetti junction of lines that the usermust guide it across.

SML: Spatial Manipulation Language. A pro-gramming language for manipulation ofthe geospatial objects in the TNT prod-ucts. SML allows you to enter either im-mediate commands or to write a full pro-gram. To use SML interactively, you en-ter single commands from the keyboardand SML executes each command as it isentered. To use structured programs withSML, you prepare a script ahead of time.

soil association: A soil mapping unit con-taining adjacent soils, but the survey didnot take the time and effort to delineatethem. Soil association information is suit-able for general planning only: to com-pare areas, to locate refuge tracts, andcertain kinds of land use.

soil complex: A soil mapping unit with twoor more soils so intricately mixed thatthey cannot be shown separately on themap.

soil group: (undifferentiated) A soil map-ping unit with two or more soils. For thepurposes of the map, there was little valuein separating them.

soil mapping unit: An area on a soil mapwith a complete, closed border drawn by asoil scientist, usually representing an areaof one type of soil. A mapping unit isnearly equivalent to a soil phase with the


exception of small scattered bits of othersoils that are not worth showing.

soil phase: A subset of a soil series differen-tiated by slope, stoniness, or other char-acteristics that affect the soil’s usefulness.

soil profile: The sequence of natural layers,or horizons, in a soil. A profile extendsfrom the surface down into the parentmaterial that has not been changed muchby leaching or by the action of plant roots.

soil series: A U.S. category of soil classifi-cation including soils that have similarprofiles (thickness, arrangement) namedfor a town or geographic feature near itsfirst observation. Soils in a series are es-sentially alike in characteristics that af-fect their behavior in an undisturbed land-scape.

solid modeling: The process of rendering a3D surface from vector type data. Thisprocess is widely used in CAD softwarepackages to prepare a realistic color pre-sentation of a component part, a build-ing, or other solid object from complexvector-oriented engineering drawings. InGIS vector-oriented software, contours ofthe surface of the land stored as vectorsmight be used to render a solid model ofthe land’s surface.

spaghetti digitizing: Entering line data inno particular order using a digitizer.

SPANS: The SPatial ANalysis System fromTYDAC AG.. SPANS was developed andmarketed in the 1990's.

spatial: An adjective applied to objects thatvary in space in two or three dimensions.

Spatial Manipulation Language: See: SML

speckle: The image noise typically found inradar images. Radar images with specklehave a grainy appearance that comes fromrandom variations in the strength of theback-scattered signal.

spectral band or spectral region: A well-defined, continuous wavelength range inthe spectrum of reflected or radiated elec-tromagnetic energy. Red, green, and blueare all spectral regions within the portionof the spectrum that is visible to humansas light. Color-infrared images are com-posed of red, green, and a spectral regioncommonly called the photoinfrared,which is not in the visible portion of the

electromagnetic spectrum. (See also:color-infrared, electromagnetic spec-trum.)

spherical web mercator: Google andMicrosoft tilesets structures were de-signed for global coverage using a spheri-cal adaptation of the Mercator projec-tion called the Spherical Web Mercator(EPSG code 3785). Google Earth andNASA World Wind tilesets use Plate Car-rée (Equirectangular). TNTmips tilesetscan use any projection and datum de-fined by EPSG and projections definedby other sources.

spheroid: Any shape that closely resemblesor approximates a perfect sphere. Inthe context of map projections, a spher-oid is an ellipsoid of rotation that isflattened at the poles, like the earth.

spline: An interpolating polynomial for aset of coordinate points used to fit a curvethat connects the points. (See also: Béziercurve)

SPOT: The French Systeme Probatoired’Observation de la Terre from SpotImage S.A. SPOT 1 was launched in 1986The SPOT 5 satellite, launched in 2002,provides panchromatic images with syn-thetic 2.5 meter resolution. They can becolor-enhanced with SPOT 10-metercolor images. SPOT satellites may bepointed at an angle off-axis or off-nadirto collect forward and rearward images: atechnique that yields stereoscopic imagepairs from which accurate elevation ras-ters can be computed.

spread: The spread operation changes thecolors between two selected tiles in theColor Map Editor window. TNTmipstakes the colors in the starting and end-ing tiles and assigns even color grada-tions to each tile between them. Youcan select different spread types to tellTNTmips which way to traverse thecolor space between the endpoints. (Seealso: HBS, HIS, RGB.)

sRGB: The standard color space developedby Hewlett-Packard and Macintosh.

spur: A false line segment that extends ashort distance beyond a T-junction oftwo lines. Binary raster thinning pro-cesses often leave spurs that should be


erased by raster editing before finalvectorization.

SQL: Structured Query Language. An ANSIstandard for accessing and manipulatingdatabases.

stack: A hierarchical arrangement of im-ages and other information used byHyperIndex that graphically links logi-cally related objects or files. A stack hasthe inverted tree form of a genealogychart. (See also: HyperIndex, link.)

stack profile: A series of profiles for visu-alizing a three-dimensional surface. Thestack profile is saved as CAD object.

standard attribute tables: standard at-tributes can be calculated for geometriclines and polygons in Project File for-mat and for line- and polygon-contain-ing shapefiles that are directly used. Theattributes calculated depend on the ele-ment type. For example, length and thecenter point for x, y, and z are deter-mined for lines; and area, and the cen-troid x, y, and z are determined for poly-gons, among other properties. Standardattribute tables can be created and main-tained in TNT’s Editor or created in aseparate TNT process (Geometric/At-tributes/Standard).

standard lossless: A raster compressionmethod. The compressed output fromthis method maintains 100 percent fi-delity to the colors of the uncompressedinput raster object. Standard Lossless isbest for objects that have good pixel-to-pixel correlation in the image.

standard parallel: A parallel of latitudeused as a control line in the computationof a map projection, and which is there-fore, true to scale. Some map projec-tions have no defined standard parallel,others have one, while others have two.

standard 64 annotation colors: In 8-bitcontexts the Color Palette Editor win-dow normally reserves the first 64 col-ors for a standard set of user annotationcolors for text and overlays. That leaves192 colors for the image itself - amplecolor space for representing most natu-ral color images to the human eye. The64 standard colors are chosen at fixedintervals in the RGB color model. Theygenerally appear brighter and purer than

the subdued natural tones of the underly-ing image.

State Plane Coordinate System or SPCS:The State Plane Coordinate System(SPCS) defines map coordinates by zonefor the United States. Each zone has onecentral meridian and scale factor, whichpermits all USGS quadrangle maps in azone to be mosaicked exactly. Zones withgreater north-south extent use the Trans-verse Mercator projection, while thosewith greater east-west extent use Lam-bert Conformal Conic. (The panhandleof Alaska is the only exception, and usesOblique Mercator).

stepwise linear classification: A super-vised image processing routine applied inthe same fashion as maximum likelihoodclassification using training sets, or pro-totypes. This method applies the classi-cal techniques of stepwise linear discrimi-nant analysis to set up the classificationmodel and map the materials desired fromthe input raster objects. (See also: maxi-mum likelihood classification)

stereo elevation: An elevation surface de-rived from stereo pairs of remote sensingimagery. For example the SPOT satellitecan collect an “off nadir” image and thenin a subsequent fly-over collect its coun-terpart to make a stereo pair. The stereoelevation process takes the 3D effect ofthat stereo pair to derive an accurate ras-ter object of elevation values.

stereo viewing: An elevation raster and animage overlay are combined to produce a3D effect when viewed with a stereo view-ing device (e.g., anaglyph glasses).

style query: (in database queries) A stylequery is constructed from a combinationof comparison expressions, which exam-ine values of element and database vari-ables, and assignment statements, whichset the values of drawing variables.

stop: (also called a waypoint) an intermedi-ate point along a route that must be vis-ited and is consequently included in yournetwork analysis.

Sub-extremum: A method for calculatingimportant points in the Irregular 3DPoints method of the Extract ImportantPoints process.


subobject: A component of a TNTmipsproject file attached to a primary object.A subobject contains data that describessome aspect of the primary object. Ex-amples: 1) map registration informationis kept as a subobject (Regist) under theraster object it calibrates; 2) a pseudo-color table is kept as a subobject (ColMap)under the raster object it describes; 3) aHyperIndex subobject attached to a vec-tor overlay polygon maintains the linksTNTmips uses to retrieve that polygon’sassociated daughter objects.

subtractive color: Creating color by usingabsorption or scattering to selectively re-move some of the colors of light, or ra-diation, reaching the human eye is a sub-tractive process. The use of pigments,such as color printing or a painting, dem-onstrate this subtractive color process.The greater the number of different col-ored pigments mixed together, the darkera pigmented object appears. This dark-ness results from an increased absorptionof visible light by the pigments and, con-sequently, less light reflected to the eye.The presence of fewer pigments or theirabsence altogether results in greater re-flectance of visible light. Selective ab-sorption removes a color(s) from the re-flected radiation and results in the per-ception of the complementary color.

subwindow: An auxiliary window that opensas the result of some user action in theparent window (such as pressing a but-ton), or of some processing condition (adialog box subwindow might open with amessage or warning.)

Suits’ Maximum Relative classification:A supervised Auto-Classify method thatis computationally quicker than the othermethods. The algorithm for this processcomputes the composite brightness andthe ratio of each band brightness to thecomposite brightness. The mean and stan-dard deviation of each of these param-eters is then calculated for a class and usedto define the class boundaries.

Suits-Wagner classification: A simpleform of supervised or semiautomatic clas-sification that operates similarly to a box-car or parallelepiped classification. Thismethod defines the sides of the box for

each class as plus and minus one standarddeviation from the mean of the valuesof the prototype, or sample, values se-lected to represent that class. Thismethod has the advantage that like asimple boxcar classifier, it is very fast toapply the resulting decision rule to theunknown pixel values. More informa-tion on this process can be found in: H.L.Wagner and G.H. Suits (1980) Proceed-ings of the 14th International Sympo-sium on Remote Sensing of the Environ-ment, vol. III pp. 1525–1529. Envi-ronmental Research Institute of Michi-gan, Ann Arbor Michigan. A Low CostClassification Algorithm for DevelopingCountries.

supervised classification: A type of auto-matic multi-spectral image interpretationin which the user supervises feature clas-sification by setting up prototypes (col-lections of sample points) for each fea-ture, class, or land cover to be mapped.TNTmips statistically analyzes these col-lections of points to characterize eachfeature and then maps them by math-ematical comparison.

surface fitting: Techniques that use 3-di-mensional vector point data to create araster object containing an elevation sur-face. Various methods can be used to fillthe gaps between the vector points andderive the elevation values for the inter-mediate raster cells.

surface object: A raster object whose cellvaluse are used as elevation values to de-fine a three-dimensional surface overwhich other objects can be draped.

SVG: Scalable Vector Graphics. A W3C stan-dard for vector graphics based on XML.

S-video: Separate video. S-video maintainsthe video in two separate signals: lumi-nance and color.

symbol hot spot: The place on a TNTmipssymbol that controls its position. TNT-mips locates a symbol by putting its hotspot on the point that provides its coor-dinates. Every symbol has a hot spot: itdefaults to the center of the symbol de-sign area, but may be relocated. The hotspot is also called the origin.

symbol overlay: A vector object can havesymbol shapes assigned to some or all of


its point features. When this vector ob-ject is displayed over (or overlaid on) animage, you can also choose to displaythe symbols over the top of the featuresin the underlying image. Such symbolsmay also be attached to database recordsand used to graphically retrieve such ref-erence information. For example, a sym-bol overlay that uses ducks to representnesting sites could be shown over a habi-tat map. A click on a particular ducksymbol could retrieve a record from anassociated database and display it on thetext screen to provide such informationas the date of first occupancy, number ofeggs, number of fledglings, and so on.(See also: overlay.)

symmetric minima: A raster cell that hasa value less than two opposite neighborsin any direction. A raster object of sym-metric minima is calculated from an el-evation raster object and provides a rep-resentation of the relative roughness ofterrain. TNTmips includes symmetricminima and flats (see above) in the sameoutput raster object.

synthetic resolution: An apparent increasein spatial resolution achieved either byresampling image rasters or by combin-ing images from different sensors of vary-ing resolutions (such as SPOT panchro-matic and TM multispectral).

system table: one of a few table types notshown to the user by default. Systemtables include style assignment tables forall geometric object types and internaltables for vector, shape, and TIN ob-jects. Some raster object types also havean internal table. You can show systemtables from the right mouse button menuat the element level in a layer managerwindow (See also: internal tables.)

— T —tab group: (also, “Field”) A component of

a window such as a button, list, scroll bar,pane, sash, or slider (sometimes “scale”)that can be selected with the locationbox by pressing the Tab key. Some tab

groups, such as a selection list, can becomposed of multiple items throughwhich the location cursor can be movedby the arrow keys.

table: A database is organized into tables thatcontain records. Tables cover differenttopics related to the same common theme.The theme and its extent of developmentdetermine the number of tables that com-prise the database. For example, the CrowButte soil polygon database containstwelve tables, in such areas as yield, croppotential, and statistical information. (Seealso: database object, field, record.)

tag: A temporary number that can be as-signed to a class in the Training Set Edi-tor of the Auto-Classification process. Forexample, you import a set of classes intothe Training Set Editor. Each class has avalue when it is imported. If a class doesnot have the value that you want to use,you can assign a tag number to the class.You can assign different tag numbers toas many different classes as you wish.When you assign the same tag number tomore than one class, the Training SetEditor merges the classes.

tail: The portion of a distribution curve thathas few values and extends away from thepeak area of the curve where most valuesare located.

TARGA file: Truevision Advanced RasterGraphics Adapter file. The TGA formatsupports color maps, alpha channel,gamma value, postage stamp image, tex-tual information and developer-definabledata.

Tasseled Cap A transformation that rotatesfour LANDSAT MSS bands such that themajority of information is contained intwo components or features that are di-rectly related to physical scene charac-teristics, brightness and greenness. Thetasseled cap transformation is used foragricultural crop monitoring.

TCP/IP: Transmission Control Protocol/In-ternet Protocol are low-level communi-cation protocols that allow computers tosend and receive data.

template: A hardcopy layout with designatedconstant and changing layers and groups.A template automatically prompts for re-


placement layers for those designated aschanging when opened.

terabyte, Tbyte, or TB: A unit of measure-ment for 240 (approximately)1,000,000,000,000 bytes, 1,000,000,000kilobytes, 1,000,000 megabytes, or 1000gigabytes. (See also: bit, byte, exabyte,gigabyte, kilobyte, megabyte, petabyte,exabyte, zettabyte, yottabyte.)

terrain: The elevation raster used to providesurface values for a 3D simulation, suchas in TNTsim3D.

terrain tileset: A tileset designed for pre-sentation of surface elevation informa-tion particularly for 3D stereographic view-ing.

terrain scene: A rendering of geometric rep-resentations of geographic entities upona land surface in such a way as to simulatethe view of a human observer. (OpenGISConsortium)

Terra-Mar: An early vendor of a raster-basedmicrocomputer image processing and GISsystem.

text: A string of characters grouped in a file.

text cursor: A graphic mark such as a blink-ing underscore, vertical line or character-sized box on the screen that indicates thefocus of keyboard text entry and editing.

text field: A component of a window thatcan be selected with the location box fortextual information that can be enteredand edited from the keyboard.

text monitor or text screen: (historicalterm) In the old DOS MIPS (v3.3 andearlier) The B/W or color monitor usedto display text materials (like menus, da-tabase records, and keyboard input). MIPSused a second screen (the display moni-tor) for images and maps.

text object: Anything from a simple stringof ASCII characters to a more complex,formatted page description. A text objectmay be output from some TNTmips pro-cess, reference information created by atext editor, or a file generated by a wordprocessing program.

texture: The raster used as a surface drape ina 3D simulation, such as in TNTsim3D.

theme: The common property used to orga-nize vector data into separate objects, such

as soils, hydrology, and roads.

theme map: A map that uses a color gradi-ent to illustrate the variation of a quan-titative attribute, such as population orincome.

Thiessen polygons: Polygons that boundan area closest to the points that formthe boundary than to any other points.TINs are more efficient than other datastructures at generating Thiessen poly-gons. They are also known as Voronoidiagrams.

thinning: (rasters) To remove cells fromwide line images in a raster object. Whena scanner creates a raster object, the linesin the drawing typically are several cellswide in the result. Some automaticvectorization techniques work on thedata after the line images in the rasterobject have been thinned to make theline images just one cell wide.

thinning: (vectors) Reducing the numberof coordinate pairs that describe avector’s line and polygon elements.Some of the coordinate pairs will be dis-carded when straight line lengths replacecurved or noisy segments in the originallines.

threshold: (binary) The separation pointfor converting grayscale raster cell datainto binary (black and white) data. For araster object scanned with 256 levels ofgray, a threshold might be set at 180.Then the output binary raster objectwould have a 1 for every cell in the inputraster object that had the value 180 orhigher, and 0 everywhere else.

thresholding: Setting a data conversionseparation limit such that any incomingvalue above the designated limit, orthreshold, is assigned one value (in bi-nary thresholding, a “1”) and any in-coming value below or equal to the limitis assigned another value (in binarythresholding, a “0”). Thresholding canbe used to generate a binary raster from a16-gray-level scan, or to find featureedges during the steps of raster to vectorconversion.

tick mark: A line that sticks out or in alonga map grid boundary that may also occurinternally at specified intervals.


tie point: A point that is co-located on tworaster objects that have an overlappinggeographic extent. Tie points are usedin the manual mosaic process to estab-lish the relationship between adjacentpieces of the mosaic that provide no ab-solute ground control information, butdo show some common ground featurein each piece. For example, multipleframes of airvideo can be tied togetherwith tie points (farm buildings, field cor-ners, bushes, rock outcroppings, bends instreams) even if the map coordinates arenot known for such features. Then, themap calibration for the entire sequencecan be established from control pointssparsely located in the mosaic sequence(such as road intersections) for which themap coordinates are known. (See also:control point.)

TIFF: Tag Image File Format. A series ofimage file formats designed to transferimages between different software pack-ages. .TIF files are wildely used forlossless 24-bit color images.

TIGA: (historical term) Texas InstrumentsGraphics Architecture. An early soft-ware interface that standardized commu-nication between application softwareand display boards that used one of theTMS340 chips. TIGA divided tasks be-tween the TMS340 display processor andthe CPU of the host microcomputer toimprove performance and generalize dis-play driver requirements.

TIGER files: topologically Integrated Geo-graphic Encoding and Referencing filescompiled and distributed by the U.S. Cen-sus Bureau.

tile column and row numbers: tiles inGoogle Maps, Bing Maps, and WorldWind tileset structures are aligned to apredetermined global grid at each zoomlevel. The position of each tile withinthe grid is indicated by its tile columnnumber (east-west position) and tile rownumber (north-south position). Tile rowsare numbered from top to bottom andtile columns from left to right, each be-ginning with 0 in the upper left corner ofthe global grid. In tilesets using the BingMaps flat quadkey structure and the WorldWind structure, tile column and row num-

bers are encoded into the filename foreach tile file. In the hierarchical tilesetstructures created for use in Google Mapsand Bing Maps, tile files are named bytheir tile column number and grouped indirectories named for their tile row num-ber.

tile format: The formats that can be used ineach type of tileset structure are dictatedby the application that that will use thetileset and the specific uses within thatapplication. Although the allowed for-mats vary, Google, Bing Maps, and WorldWind tilesets all support the use of JPEGand PNG tile file formats.

tile map: A tile map identifies which tiles areavailable in the corresponding tileset. Itlets you examine a tilesets spatial cover-age, assess its completeness, identify miss-ing tiles, and view the file format of tiles.A tile map is a series of TNT raster ob-jects, one for each zoom level in the tile-set. Each tile map raster has one cell foreach tileset tile. The cells are color-codedto indicate the file format of the corre-sponding tile file (green for JPEG, red for8-bit PNG tiles, and yellow for 24-bitPNG tiles).

tiles: Rectangular areas of defined size in araster object used for storage of the in-formation. Storing raster objects in tiledformat generally increases display speedwhen viewing less than the entire object.

Also, raster object image pieces that areassembled and trimmed in the TNTmipsmosaic process or one of the other pro-cesses on the Tileset menu. (See tilesetsfor more on this use of the term.)

A third usage of the word tiles occurs inthe Color Map Editor where the upperpart of the window displays the colors inthe map with small sample squares, ortiles. The active or selected tile is out-lined in white, and its cell value and alarger sample is displayed below.

tileset: A multifile object in a predefined struc-ture designed for very efficient viewingof geodata particularly over the Internet.A tileset can range from a few tiles cover-ing a local project to 100s of million tilescovering a continent or the globe.TNTmips can generate tilesets in its ownstructure and in Google Maps, Google


Earth, Bing Maps, and World Wind struc-tures.

A tileset structure is the most efficientway to store each image for use in a geo-mashup. Its hierachical directory struc-ture and small compressed tiles, which areprecomputed at each available zoom level,permit an image of any size to be effi-ciently viewed in a geomashup. Viewingor adding any part of a tileset to a geo-viewer requires reading only a few smalltiles from any available Internet sourcethat is hosting it.

tileset cache: Tiles are downloaded cachedlocally when initially requested. The tilecache can be cleared using the Clear tile-set cache button on the Storage tabbedpanel of the General System Preferences(Tools/System/Preferences) or from theOptions menu in the Display Manager.

tileset size: The time it takes to view orrefresh a view of a tileset is independentof its size. Any view always directly ac-cesses and reads the few tiles that are re-quired at the view’s scale or zoom level.The tileset’s directory hierarchy meansthat any individual tile can be directlylocated. The small tiles, made evensmaller by lossy compression, insure thatthey can be rapidly read even when theyare read over the Internet or a local net-work or even from a DVD. A single tile-set can contain a few thousand or 100s ofmillions of tiles in a single directory struc-ture.

tileset structure: A tileset can be flat, withall tile files in a single directory, or use ascale-pyramided hierarchical directorystructure of tile files. MicroImages’ tilesetraster objects are also hierarchical tilesetstructures.

tiling: Assembling large images from smallersegments that have common angular ori-entations, cell sizes, and map projections.The process is similar to that of assem-bling floor tiles, except that the rastertiles may overlap at the onset. (See also:montage, mosaic.)

TIN Densification: A DEM extractionmethod that builds a TIN surface fromthe initial set of user-supplied tie points,and then iteratively densifies the TIN ob-ject. The process looks in the middle of

each existing triangle and adds a new nodewhen it finds a point of high correlation.Then it recomputes the local topologyand goes on to the next triangle.

TIN elements: TNTmips TIN objects con-tain four element types: nodes, edges,triangles, and hulls. Nodes are the mostfundamental element of a TIN and theonly element type that references spa-tial coordinates (x,y,z). An edge is anoriented line segment that connects twonodes. Three edges connect three nodesto form a triangle that satisfies theDelaunay criterion. Triangles representelementary areas of the surface that de-scribe topological relationships betweenall other elements of the TIN data. Ahull represents the area covered by a TINstructure. Interpolation of z-values isonly valid within a hull region.

TIN object: A TIN, or Triangulated Irregu-lar Network, object represents a continu-ous surface as a set of conterminous tri-angles computed from irregularly spaced3D points. TIN topology is more re-strictive than the topology of other co-ordinate data objects; every node is partof some polygon, every polygon is a tri-angle, and every triangle satisfies theDelaunay criterion. (See also: Delaunaycriterion.)

title bar: The area across the top of a win-dow that displays the name of the win-dow, the resize graphic, the iconifyingbutton, and the close button.

TM: Thematic Mapper. A sensing device onthe Landsat satellite that scans and stores7 individual images in spectral bands rang-ing from the blue wavelengths up to thosein the thermal infrared.

TNTatlas®: A free product in the TNT fam-ily for publication of spatial data that isgraphically organized into stacks forpoint-and-click navigation through all in-formation of interest. An atlas may alsobe a single display or page layout with orwithout layer visibility controlled by mapscale.

TNTbrowser™: A free, standalone Javaapplet for use with TNTserver. This prod-uct was supplanted by TNTmap Builderand TNTmap Viewer. Now web tilesetsproduced in TNTmips and your browser


are used for viewing your and others GISdata over the web.

TNTclient™: MicroImages’ free applet forweb browsers that works with TNTserver.TNTclient can be requested in Java orHTML versions. This product was sup-planted by TNTmap Builder and TNT-map Viewer. Now web tilesets producedin TNTmips and your browser are usedfor viewing your and others GIS data overthe web.

TNTedit™: Provides professional, interac-tive tools to create, georeference, andedit project materials consisting of vec-tor, raster, CAD, TIN, and relational da-tabase products.

TNTlite®: A free version of TNTmips forsmall-scale projects. TNTlite is not ademo, but a full-featured geospatialanalysis software package (now calledTNTmips Free).

TNTmap Builder: Lets you select and ar-range map layers from any number ofWMS sources. Launches views of se-lected layers in your choice of TNTmapViewer or other WMS viewers, such asGoogle Earth, Google Maps, or NASA’sWorld Wind.

TNTmap Viewer: Lets you view map layersfrom any number of WMS sources. Thisviewer is launched from the layers se-lected in TNTmap Builder.

TNTmips®: The latest, full-featured versionof the Map and Image Processing Sys-tem from MicroImages, Inc.

TNTmips® Basic: A very low cost version ofTNTmips for small-scale projects.TNTmips Basic is not a demo, but a full-featured geospatial analysis softwarepackage with support for larger imagesthan allowed by TNTmips Free.

TNTmips® Free: A free version of TNTmipsfor small-scale projects. TNTmips Freeis not a demo, but a full-featured geospa-tial analysis software package.

TNTsdk®: A software development kit forcomputers equipped with a full TNTmipslicense to create custom products for dis-tribution and use with the TNT prod-ucts.

TNTserver™: Lets you directly publish overan intranet or the Internet your geodata

(raster, vector, CAD, relational database,and other layer types) from TNT ProjectFiles and other popular geodata formats.This product is no longer supported be-cause technological advances have madeit obsolete.

TNTsim3D™: A free, standalone program forWindows that lets you fly over 3D ter-rains with keybord or joystick controls.This product is no longer supported be-cause you can now view your geospatialdata created in TNTmips in 3D in GoogleEarth.

TNTview®: Provides the visualization capa-bilities of TNTmips and some interpre-tive abilities for those who do not requirethe full set of features included in TNT-mips.

toggle button: A toggle button offers an on/off control option for the current pro-cess. A toggle button’s label tells whatstate it controls, and it is preceded by agraphic indicator of the on/off state ofthe button.

toolbar: Row of icons appearing below themenubar that provides direct access totools and other actions.

ToolTip: A ToolTip pops in naming the menuitem selection that duplicates the func-tion of the icon button when the mousecursor pauses over an icon button.

topographic map or topo map: A map thatuses colors and symbolic patterns to rep-resent the general surface features of theearth, such as grassland, forest, marsh,agricultural, urban, and barren rock.

topography: The features of the actual sur-face of the earth, considered collectivelyaccording to their form (for example,grassland, cultivated, desert, forest,swamp). A single feature, such as onemountain or one valley, is called a topo-graphic feature.

topology or vector topology: A descriptionof the relationship between node, line,and polygon elements in a vector object.Three levels of vector topology are avail-able for RVC vector objects: polygonal,planar, and network. Polygonal topol-ogy is the highest, or strictest, level oftopology. Polygonal topology requiresthat no two nodes have the same X and Y


coordinates, all lines start and end innodes, lines do not intersect without sepa-ration by nodes, enclosed areas are de-fined as polygons, and any point can be inat most one polygon. Planar topologyrequires that all lines start and end in nodesand lines do not intersect without separa-tion by nodes, just as for polygonal ob-jects. However, polygon information isnot maintained (which means planar ob-jects have no polygons). Network topol-ogy places nodes at the start and end ofall lines, but lines may cross themselvesor other lines and there are no polygons.All three topology types may be either2D or 3D. Topology for polygonal andplanar 3D objects is maintained in the X-Y plane, which means that polygon di-mensions and the location of nodes sepa-rating lines that would otherwise cross aredetermined by projecting onto the X-Yplane. The constraint imposed by 2Dtopology on 3D objects is eliminated bynetwork topology, which allows two nodesto have the same X and Y coordinates.

Polygonal topology is necessary for ob-jects such as soil maps and property own-ership maps. Planar topology may besuitable for hydrology in the absence oflakes or road systems that lack underpassesand overpasses or other features that re-quire network topology for correct rep-resentation.

topology errors: Violations of the TNT-mips vector topology, such as line ele-ments with polygonal or planar topologythat are missing nodes at the point ofintersection, or polygons with polygonaltopology that overlap without definingan intersection polygon. TNTmips pro-cesses that refer to the vector topologyinformation either will not work, or willreturn erroneous results if the input vec-tor object has topology errors.

trace: To create a vector line element bymanually or interactively tracing over lineimages in a raster object.

training set or prototype: A group ofsample cells in an image known to repre-sent a feature type or ground cover ofinterest defined by the user from his orher knowledge of the site (perhapsthrough ground visitation or detailedairphoto interpretation).

transcoder: A device that converts videosignal formats from an input type (likeSVHS) to an output type (like RGB ana-log).

transfer rate: The number of XY coordi-nate pairs produced per second when youare digitizing with the streaming method.

Transformed Vegetation Index: A com-monly used vegetation index derived fromimages of certain spectral bands. TheTVI is equal to the square root of thequotient of the photo-infrared minus thered band, and the photo-infrared plus thered band {SQRT[(IR - red) / (IR + red)]}.Common color-infrared image sourcesthat TNTmips uses to compute TVI in-dex rasters include Landsat MSS and TM,SPOT CIR, 35mm CIR film, 9" CIR film,and CIR video.

translation curve: The curve used to ad-just a raster object’s cell values to thebrightness values used for display. TNT-mips offers a selection of different trans-lation curves (including linear) that arenormally selected to strengthen the vi-sual contrast in the display representa-tion.

transliterate: To represent the words ofone language, with the alphabet of an-other language. Usually the language isforeign to the reader, and the alphabet isfamiliar.

transparent color: The ability to overlayone color image over another image ormap so that the spatial details of bothare revealed for comparison is achievedwith transparent color. The colors thatresult from such an overlay depend onwhether the color in the images is addi-tive or subtractive.

transparent patterns: Patterns that onlypartially obscure the image upon whichthey are superimposed are transparent.For example, a pattern could consist of adrawing of a duck that leaves the remain-der of the pattern tile transparent. Whenthis pattern is used to fill a polygon thatcontains a lake, the lake colors and fea-tures will be visible through the transpar-ent portions of each tile.

trend: A steady change in contrast across animage. The change is introduced by thecollection device or by the geometric ori-


entation of the instrument in relation tothe Earth’s surface.

TriDEF: An inexpensive application thatconverts Google Earth views into stereousing DirectX (Windows only).

tropic of Cancer: the parallel 23° 27' northof the equator that marks the position atwhich the sun is directly overhead at thesummer solstice. This latitude is thenorthernmost latitude reached by theoverhead sun.

tropic of Capricorn: the parallel 23° 27'south of the equator that marks the po-sition at which the sun is directly over-head at the winter solstice, which is thesouthernmost latitude reached by theoverhead sun.

true scale: At large sizes, every map pro-jection distorts the scale of distance, es-pecially towards the edges. The locationof the true scale of a projection identi-fies the position where map measure-ments correctly correspond to actual sur-face distances.

TSD: Tileset definition file extension. A tile-set definition file defines the locationand properties of a tileset. This defini-tion may be for a local tileset (both theTSD and tileset files reside on an attachedstorage device or a local network), a re-mote linked tileset (TSD resides on a lo-cal drive but the tileset is on the Inter-net), or an Internet tileset (TSD and tilesreside on the Internet).

TSR: (historical term) Terminate and StayResident. Under DOS, a software pro-cess that became resident in memorywhen executed and performed some spe-cial activity when the appropriate con-ditions were detected. For example, ATSR program could be loaded to memoryand wait for a particular non-standardseries of keystrokes to initiate printing atext screen out on paper.

TVI: See: Transformed Vegetation Index.

TYDAC: Formerly, a raster-based commer-cial GIS system. More recently, a pro-vider of ESRI and MapInfo software alongwith consulting and related services.

— U —underlay: To place a raster object so that it

appears to be behind an existing object orimage and will show around the perimeterand through any internal data holes inthe object on top.

undershoot: A line that does not quite meetthe line it was intended to intersect withleaving a gap.

Unicode: A character encoding scheme thatis a super set of ASCII and Latin-1 withroom for 65,536 characters (a 16-bit or2-byte set). The Unicode standard is stillin committee; it is in the care of the In-ternational Organization for Standardiza-tion (ISO) and Unicode, Inc. (formerlythe Unicode Consortium). Unicode itselfis a subset of ISO 10646, and in terms ofISO 10646, Unicode is the “Basic Multi-lingual Plane.” Unicode is designed toinclude all characters needed for the writ-ten languages of the modern world.

union: A merging of two vector objects suchthat all the elements from two objectsare copied to the resulting vector.

unsupervised classification or automaticinterpretation: The operation of a groupof multispectral image interpretationfunctions (such as K-means) that statisti-cally cluster cells into similar collections.When the classification procedures arecomplete, you identify and label theground features or conditions that the clus-ters represent.

URL: Uniform Resource Locator.

USB: Universal Serial Bus. An external pe-ripheral interface standard that usesbiserial transmission created in January1996.

USDA: United States Department of Agri-culture.

USDI: United States Department of the In-terior.

USF&WS: United States Fish and WildlifeService of the USDI.

USGS: United States Geological Survey.


UTM: Universal Transverse Mercator mapprojection.

— V —variable: (in database queries) A named en-

tity that has an assigned value. There arefour kinds of query variables: (1) thoseare associated with the vector elements(like numlines, class, and startnode); (2)those which are fields from a database(perhaps Name, Acres, and Yield); (3)those which control the drawing styles ofvector elements (like size, color, andfillcolor); and (4) the ten temporary uservariables for numeric operations (temp0,temp1, temp2 ... temp9). For example,the point element variable “size” can havea value from 1 to 64. It controls the sizeat which a point element is drawn. Anassignment statement can change onlythe values of drawing style and tempo-rary variables; it cannot change the valueof variables that are associated with a vec-tor element or a database.

variogram: A plot of the degree of spatialcontinuity based on the control points,that is points of known value in a vectoror database object with continuous geo-data. Variograms are used by the Krigingmethod in the Surface Fitting operationof Surface Modeling.

vector: “A quantity possessing magnitude anddirection, represented by an arrow, thedirection of which indicates the directionof the quantity and the length of which isproportional to the magnitude” (RandomHouse). In connection with GIS and com-puter graphics, this term is used moreloosely to refer to a set of vectors joinedend to end to make an arc or irregular linewith a uniform set of properties. TNT-mips uses this looser definition and alsoimposes topology and attaches a set ofattributes to the vector in place of themagnitude in the Random House defini-tion.

vector element: A vector object is made upof three basic types of elements that canhave associated attributes 1) points, whichare single sets of coordinates that define

a point feature (such as a well); 2) lines,which are curvilinear strings of coordi-nates that define a curved line (such as astream); and 3) polygons, which are col-lections of lines that inscribe an area (suchas a lake). A fourth type of element,nodes, are necessary to maintain vectortopology.

vector format: A data structure for repre-senting point and line data by means of2- or 3-dimensional geometric (Carte-sian x,y or x,y,z) coordinates with topo-logical requirements (see the followingdefinition for vector topology). In con-nection with GIS and computer graphics,“vector” can refer to a set of line seg-ments joined end-to-end to make acurved path in space. Vector objects alsohave a set of attributes (such as ID num-ber, color, drawing style) attached tothem.

vectorize: A general term for any techniquethat converts raster data into vector data.

vector object: A collection of vector ele-ments and attributes stored in a complextopology as one entity in a TNTmipsproject file. (See also: vector topology).

vector topology: A description of the rela-tionship between node, line, and poly-gon elements in a vector object. Threelevels of vector topology are availablefor RVC vector objects: polygonal, pla-nar, and network. Polygonal topologyis the highest, or strictest, level of to-pology. Polygonal topology requires thatno two nodes have the same X and Ycoordinates, all lines start and end innodes, lines do not intersect without sepa-ration by nodes, enclosed areas are de-fined as polygons, and any point can bein at most one polygon. Planar topol-ogy requires that all lines start and end innodes and lines do not intersect withoutseparation by nodes, just as for polygo-nal objects. However, polygon informa-tion is not maintained (which means pla-nar objects have no polygons). Networktopology places nodes at the start andend of all lines, but lines may cross them-selves or other lines and there are nopolygons. All three topology types maybe either 2D or 3D. Topology for po-lygonal and planar 3D objects is main-


tained in the X-Y plane, which meansthat polygon dimensions and the loca-tion of nodes separating lines that wouldotherwise cross are determined by pro-jecting onto the X-Y plane. The con-straint imposed by 2D topology on 3Dobjects is eliminated by network topol-ogy, which allows two nodes to have thesame X and Y coordinates.

Polygonal topology is necessary for ob-jects such as soil maps and property own-ership maps. Planar topology may besuitable for hydrology in the absence oflakes or road systems that lack under-passes and overpasses or other featuresthat require network topology for cor-rect representation.

vector units: The units in which vectorcoordinates and vector object extent areexpressed. These units are specific toindividual vector objects and are depen-dent on how the vector was created. Theunit size may be a screen pixel and theobject extents the same as the drawingarea in pixels if the vector object wasdrawn without a reference object. Theunit size is related to the number of ras-ter cells if the vector is created using anungeoreferenced raster for reference; theobject extents equal the number of rastercells times the cell size. The units corre-spond to geographic coordinates and theobject extents correspond to the geo-graphic extents if the vector is createdover a georeferenced object.

vegetation index: The output from stan-dard manipulations of multispectral im-age raster objects. The system processesthe input spectral information and cre-ates output raster objects whose cell val-ues represent the site’s biophysical prop-erties: amount of vegetation, leaf area,greenness, brightness, and wetness.

VersaCAD: A popular, commercial micro-computer Computer Aided Design (CAD)software package developed and mar-keted by Archway Systems, Inc.

vertex: The point at which a line changesdirection or terminates.

VESA: Video Electronics Standards Associa-tion. An international standards organi-zation for computer graphics founded in

1989.

VGA: Video Graphics Array. A microcom-puter video subsystem introduced by IBMwith the PS/2 microcomputer in 1987 withsupport for 256 simultaneous colors. TheVGA was an enhancement of the olderEGA. (See also: CGA, EGA.)

VHS: Video Home System. A popular for-mat for low-cost video recording andplayback, common in home video sys-tems.

video capture: Some image display boardshave the ability to display live broadcastor taped programming and then freezeand grab an image, storing it in thecomputer’s memory or on disk.

video digitizing board: A video interfacecircuit board installed in a PC that samplesor frame-grabs a video frame and con-structs a digital image. Video digitizingboards can be used for non-standard, higherresolution video sources. (See also: frame-grabbing.)

video field: The image you see on a standardTV screen is composed of a set of about480 horizontal lines. The lines are pro-jected in two passes of the signal beam.Each pass only projects every other lineof the image: the odd lines in one pass,and the even lines in the next pass. Onescan takes 1/60 of a second, so the wholepicture (the frame) is refreshed every 1/30th of a second.

A field contains every other line of thecomplete video image. The primary fieldcontains the odd lines; the secondary fieldcontains the even lines.

video frame: A complete video image, whichconsists of two interlaced fields Odd linesof the frame are contained in the pri-mary field which is alternated with thesecondary field which contains the evenlines. The primary field lasts 1/60 of asecond in standard broadcast video. Thesecondary field follows in the next 1/60of a second. The entire frame takes 1/30of a second to display. There is a differ-ence of 1/60 of a second between alter-nate lines in the image.

view: The current contents of the view can-vas.

view canvas: The area of the View window


used for layer display.

viewshed: The boundaries of sight from asingle vantage point, assuming an unob-structed surface (disregard trees and build-ings). The TNTmips Viewshed processtakes an elevation raster object, and com-putes the viewshed for selected points inthe area.

view window: The TNTmips display pro-cess always works with at least two win-dows: the control window and one or moreview windows. The control window pre-sents process options and controls, andthe view window displays the images.

vignetting: Darkening at the edges and cor-ners of an optical image. Vignetting oc-curs because lenses are physically unableto pass as much light to the fringe of anoptical field as they do to its center. Sev-eral techniques compensate for vignett-ing, but it is almost always present to somedegree. For color rasters, vignettingmeans that the color of a feature at theedge or corner of an image may not matchthe color of that same feature in the cen-ter.

virtual display: A display managementscheme that displays as much of an imageas will fit on the monitor, while bufferingthe rest of the image in a temporary filefrom a RAM disk or the hard drive. Theuser never needs to give new file infor-mation in order to access another por-tion of the image. A virtual display workslike a window that can slide anywhere ona raster object. How quickly it movesdepends on the hardware available.

virtual field: A TNTmips database field thatdraws information from other databasefields. This information can be used di-rectly or combined with the informationfrom other fields or additional compo-nents. There are two types of virtualfields: numeric, which are referred to ascomputed fields, or strings, which arecalled string expression fields. An ex-ample of a computed field is populationdensity, which may take population fromone table, area from another, make thedivision and apply appropriate conver-sion factors for the desired output units.A string expression field might concat-enate the contents of separate fields, such

as section, township, and range or createa multiline DataTip from a number ofdifferent fields, such as address, ownername, and property value for a parcelsvector object.

virtual process: (for MIPS v3.3 and ear-lier) An operation performed on a rasteror vector object that is bigger than thedisplay screen (rasters up to 32,000 x32,000 cells and vector collections of upto 2 billion coordinate pairs). You set upand guide the process on the displayscreen, and the system applies the pro-cedure to the whole image.

VMap0: An improved version of the DCW,also distributed by NGA. VMap1 is ahigher resolution of VMap0 and is alsopublicly available. VMap2 is classified.

volume: An individual storage device suchas a tape or floppy disk.

VPF: Vector Product Format is used by NGAfor the digital distribution of its map prod-ucts (DCW, VMap0...)

VQ Filtering: An image transformationprocedure in Hyperspectral Analysis.This procedure is related conceptuallyto the Self-Organizing Map (SOM) clas-sifier. The VQ Filtering procedure ap-plies the SOM classifier to the image toderive 256 spectral classes and assignseach image cell to the class with the closestmean value in spectral space. The re-sulting residual (filtered) image of eachinput band shows how well each cell fitsits assigned class at that wavelength.

— W —warping: Any process in which an object is

stretched differentially so as to changeits internal geometry. This shape changecould be defined by any one of manytransformations, such as changing a mapprojection, trilateration to change theabsolute position of specified nodes inthe vector object, fitting a polynomialto a surface, least squares movement ofcontrol nodes, and so on.

watershed: The entire area drained by astream and all of its tributaries, with all


runoff draining to the same outlet. Innature the outlet may be a lake, the ocean,or other water body. In the Watershedprocess, the outlet may also be the pointwhere a particular flow path intersectsthe boundary of the elevation raster be-ing analyzed. Synonym: catchment.

watershed basin: The area draining to anyparticular point in the landscape (calleda seed point); a subwatershed orsubcatchment. Standard basins in the wa-tershed process are generated usingstream junctions as seed points, so a stan-dard basin is the area drained by a par-ticular tributary system of the mainstream.

watershed outlet: The lowest point in awatershed toward which all water drains.In nature the watershed outlet may be alake, the ocean, or other water body. Inthe Watershed process, the outlet mayalso be the point where a particular flowpath intersects the spatial boundary ofthe elevation raster being analyzed.

watershed seed point: Any specified pointin the landscape used to determine theupslope area (basin) that drains to thatpoint.

waypoint: (also called a stop) an intermedi-ate point along a route that must be vis-ited and is consequently included in yournetwork analysis.

WCS: Web Coverage Service.

website: A virtual location on the WorldWide Web consisting of a collection ofinterlinked pages that collectively rep-resent a company, organization, or indi-vidual. A website is located by its URL.

Web Map Service: Produces views of geo-referenced data dynamically from spa-tial data. This specification standardizesthe way in which clients request viewsand servers describe their data holdings.

Web Terrain Service: Produces views ofgeoreferenced data over the Internet.Can provide 3D perspective views in a2D pictorial format, such as PNG, GIF,or JPEG. This specification standardizesthe way in which clients request viewsand servers describe their data holdings.

web tileset: A tileset prepared for use with a

web browser or other web application(e.g., Google Maps, Google Earth, orNASA World Wind). Such tilesets canalso be viewed in TNTmips Pro andTNTmips Basic.

wetness: The physical property mapped byKauth’s greenness, brightness, wetnesstransformations on Landsat TM images.It measures how wet the combined veg-etation and soil surface is, including thewater suspended in the vegetation bio-mass.

WFS: Web Feature Service.

widget: An interface component; that is, agraphical X object such as a button, sepa-rator, menu bar, or scroll bar. Widgetsare composed of data structures and pro-cedures. Widget manipulations are sup-ported by Xtoolkits; in particular by GUIlibraries such as the one from OSF/Motif.

window manager: A special client applica-tion in X that provides user controls forwindow size and position. Several win-dow managers are available for X. TNT-mips under MI/X with X Desktop usesthe TWM window manager.

wireframe: A graphical representation of atwo-dimensional or three-dimensionalsolid or surface by means of regularly-spaced, connected line segments. Thewireframe surface looks as if it had beenmolded by a flexible wire mesh. Com-puter systems use wireframe representa-tions for many intermediate 3D render-ings because they take much less process-ing time to create and manipulate than acontinuous-surface representation.

WMMR-MED: Weighted majority with mini-mum range-median. This is one of theraster enhancement filters. The WMMR-MED filter is a nonlinear edge-enhance-ment filter that also suppresses imagenoise (outlier values).

WMS: Web Map Service.

WORM drive: (historical term) Write Once,Read Many drive. A type of drive thatreads and writes to non-erasable opticaldisks, which are used for permanent, filestorage. Data is recorded with reflectivepits in the coating laid on the surface of aglass or metal disk. Once the pits havebeen burned into the coating, they can-


not be removed, which makes this me-dium non-erasable. (See also: erasable op-tical cartridge, erasable optical drive, op-tical disk)

W3C: World Wide Web Consortium.

WTS: see Web Terrain Service.

— X —X client: A program that uses the X server’s

services, including applications programs,which may run either on the same ma-chine or elsewhere on the network. TheGUI itself is a client. TNTmips is a cli-ent. NOTE: an X client is software, nothardware as the term “client” is used inother networking contexts.

X display: A keyboard, mouse, and one ormore screens.

X font: A file in the X Window System thatcontains the bitmapped character descrip-tions for a particular font.

Xlib: A C library of low-level X commands atthe heart of the X Window System. Xlibcommands do things like draw lines, openand close windows, fill polygons, and trackthe mouse and other user events. It ispossible to write X applications com-pletely from Xlib commands (just as it ispossible to write complicated software inAssembler), but it is easier to use higher-level commands, such as those in variousXtoolkits.

XML: Extensible Markup Language.

XNP: X Network Protocol. A high-level pro-tocol that defines data structures for com-municating between clients and servers.

X server: The X program that manages thedisplay and runs locally on the terminalor computer on the desktop. The servercontrols output to the display, handlesinput, and manages the windows, drawstwo-dimensional graphics as needed, andsends messages. For Mac OS X machines,the X server for TNTmips is provided bythe system vendor. For Windows ma-chines, MicroImages supplies its own Xserver.

Xtoolkit or Xt Intrinsics: Any subroutine

library that contains higher-level mecha-nisms than Xlib for generic tasks likedrawing window borders, scroll bars, andbuttons.

X Window System: A standard method ofhandling displays that can be used to builda windowing environment. Two popularGUI’s, Motif and OpenLook, have beenbuilt on the X standard.

X-Y digitizing tablet: A peripheral devicefor manually translating line and pointdata (like engineering and technical draw-ings) into some computer format (usu-ally vector or CAD). The drawing issecured to the tablet, and the operatorpositions the device’s cursor (which maylook like a pen or a computer mousewith a crosshair lens) over lines and otherelements, clicking a button or pressing akey to record a coordinate.

— Y —yottabyte, Ybyte, or YB: A unit of mea-

surement for 280 (approximately)1,000,000,000,000,000,000,000,000bytes, 1,000,000,000,000,000,000,000kilobytes, 1,000,000,000,000,000,000megabytes, 1,000,000,000,000,000gigabytes, 1,000,000,000,000 terabytes,1,000,000,000 petabytes, 1,000,000exabytes, or 1,000 zettabytes. (See also:bit, byte, exabyte, gigabyte, kilobyte,megabyte, petabyte, terabyte,zettabyte.)

— Z —zettabyte, Zbyte, or ZB: A unit of mea-

surement for 270 (approximately)1,000,000,000,000,000,000,000 bytes,1,000,000,000,000,000,000 kilobytes,1,000,000,000,000,000 megabytes,1,000,000,000,000 gigabytes,1,000,000,000 terabytes, 1,000,000petabytes, or 1,000 exabytes. (See also:bit, byte, exabyte, gigabyte, kilobyte,megabyte, petabyte, terabyte,yottabyte.)


zoom level: A tileset can have one or manyzoom levels. The maximum zoom levelis the most detailed, or highest resolu-tion, zoom level. The minimum zoomlevel may be the full view of an image. Aparticular tileset may have a limited num-ber of zoom levels when it is displayed incombination with other tilesets. Theprerendered zoom levels for a tileset de-termine its zoom level range,

Zoom Transfer Scope or ZTS: An optical-mechanical device produced and marketedby Bausch and Lomb. With it you canview and overlay two images throughseparate optical paths. Usually one eyeviews a reference map and the other aportion of a color airphoto. The scale,position, and orientation of either opti-cal path can be changed so that theairphoto matches the map in some localarea. You then refer to the airphoto andmark interpretation lines on the map ora transparent overlay. As the airphoto ismoved slightly to register another sub-section, you compile a map that has aminimum amount of distortion inducedby the airphoto.

— 1, 2, 3 —16-bit raster object: A raster in which each

cell is represented by two bytes (16 bits)and can therefore assume 65,536 possiblevalues. Elevation data commonly is ex-pressed in 16-bit data. When color com-posite images are stored in 16-bit rasters,5 bits represent the intensity level forred, 5 bits green, and 5 bits blue (the 16thbit is typically unused). With this scheme(32 possible levels for each color), eachcell in a 16-bit composite color rastercan take any one of 32,768 possible col-ors.

2D histogram: A two dimensional histo-gram can be created from two single his-tograms to give a visual sense of the simi-larity between the source raster objects.

24-bit raster object: A raster in which eachcell is represented by three bytes (24 bits)and can therefore assume 16,777,216possible values. When color images arestored in 24-bit rasters, 8 bits representthe intensity level for red, 8 bits green,and 8 bits blue. With this scheme (256possible levels for each color), each cellin a 24-bit color raster can take any oneof 16,777,216 possible colors.

3D surface modeling: Rendering a 3D sur-face from raster objects. Either a singleobject can be used to control both theheight and the graytone in the display, oran elevation raster can be matched with aset of color image rasters for a real-world3D image. (See also: solid modeling.)

3DMax™: Stereo shutter glasses for 3D view-ing.

3D scene: A 2D projection of three dimen-sional features into a viewing plane lo-cated at an arbitrary position and angle in3D space, in such a way as to preserve thevisual appearance of a third spatial di-mension. (Open GIS Consortium)

4-bit raster object: A raster in which eachcell is represented by a nibble (half a bite)and can therefore have 16 possible val-ues. The TNT products use 4-bit rasterobjects for class rasters having 16 or fewerclasses and for dithered print-rasters.

5-5-5 composite color conversion method:16-bit color data uses 15 of the 16 bits tostore the color intensity information: 5bits to represent the intensity level forred, 5 bits for green, and 5 bits for blue

Glossary for Geospatial AnalysisAdvanced Software for Geospatial Analysis

11th Floor – Sharp Tower206 South 13th StreetLincoln, Nebraska 68508-2010 USA

GLOSSARY

Voice: (402)477-9554FAX: (402)477-9559

email: [email protected]: www.microimages.com

IndexA.................................................................. 3

B................................................................... 7

C................................................................. 10

D................................................................. 17

E ................................................................ 22

F ................................................................ 25

G................................................................ 29

H................................................................ 32

I ................................................................ 34

J ................................................................. 37

K................................................................ 38

L ............................................................. 39

M .............................................................. 41

N ............................................................. 45

O................................................................ 47

P ................................................................ 48

Q................................................................ 53

R................................................................ 53

S ................................................................ 56

T ................................................................ 63

U................................................................ 68

V................................................................ 69

W................................................................. 72

X................................................................. 73

Y................................................................. 73

Z ................................................................ 74

1, 2, 3 ......................................................... 74

®

MicroImages, Inc.¤

MicroImages, Inc. publishes a complete line of professional software for advancedgeospatial data visualization, analysis, and publishing. Contact us or visit our website for detailed product information.TNTmips Pro TNTmips Pro is a professional system for fully integrated GIS, image

analysis, CAD, TIN, desktop cartography, and geospatial database management.

TNTmips Basic TNTmips Basic is a low-cost version of TNTmips for small projects.

TNTmips Free TNTmips Free is a free version of TNTmips for students and profes-sionals with small projects. You can download TNTmips Free from MicroImages’ website.

TNTedit TNTedit provides interactive tools to create, georeference, and edit vector, image,CAD, TIN, and relational database project materials in a wide variety of formats.

TNTview TNTview has the same powerful display features as TNTmips and is perfect forthose who do not need the technical processing and preparation features of TNTmips.

TNTatlas TNTatlas lets you publish and distribute your spatial project materials on CD orDVD at low cost. TNTatlas CDs/DVDs can be used on any popular computing platform.

TNTserver TNTserver lets you publish TNTatlases on the Internet or on your intranet.Navigate through geodata atlases with your web browser and the Web Map Servicecompliant TNTmap JavaScript and dynamic HTML client.