Getting the Map into the Computer Getting the Map into the Computer GIS Data CollectionGIS Data Collection

• Primary Data Capture

• Secondary Data Capture

Primary Data CollectionPrimary Data Collection

• Data that is created in house

• The most expensive part of a GIS– Most estimates say that this is 80% of total

cost

Manual Vector InputManual Vector Input

• Digitizing Tablet

• On Screen Digitizing

• Text Files

• COGO

Digitizing TabletDigitizing Tablet

• Sends an electrical impulse from the edges that is read by the puck to determine Location.

• Accuracy of tablets ranges form .01” to .002”

Digitizing ProcedureDigitizing Procedure

• Turn on digitizer and place map on tablet– This will let the map and tablet reach thermal

equilibrium

• Tape the map to the tablet• Register the map using control points

– Must have at least 4 control points with known location

• Digitize the features• Fix Digitizing errors (TOPOLOGY)

Two Methods of DigitizingTwo Methods of Digitizing

• Point Mode– One (X,Y) Location is captured for each click of the

puck button– More accurate– Requires less skill

• Stream Mode– The digitizer will send locations while the puck button is

held down– Requires more skill– Can be faster– Slow operators will capture many more points than

necessary

On Screen DigitizingOn Screen Digitizing

• The original is scanned and Georeferenced

• Features are captured using the mouse

• Less fatigue than using a tablet

Repetitive Motion InjuriesRepetitive Motion Injuries

• Manual digitizing can cause repetitive motion injuries.

• Work in a location that minimizes stress on wrists and shoulders

• Take breaks

• Use a splint to keep wrist bent

• Seek Medical opinions at the first signs of problems

Names for people who do Names for people who do manual digitizingmanual digitizing

• Digislaves

• Prisoners

• Grad Students

Automated DigitizingAutomated Digitizing

• Tools to automatically convert a raster scan to vector lines

• Requires a very clean scan• Scans can be cleaned using raster cleanup tools• The vector files usually require cleanup after

conversion• If you start with a clean image it can save a lot of

time• If you image is not clean manual digitizing may

be faster

Automated ToolsAutomated Tools

• Gridline– Command line ArcInfo command– Need a near prefect image– Can have a large amount of cleanup after

conversion

• ArcScan Extension– New extension at 8.3– Has clean up tools– First tools for ArcGIS that work well

ArcScan DemoArcScan Demo

Text FilesText Files

• If you have a text file or table with X,Y values you can directly import them into ArcGIS.

• GPS Data

COGO and Survey AnalystCOGO and Survey Analyst

• COGO Coordinate Geometry– Extension for Command line ArcInfo

• Tracking Annalyst– ArcGIS Extension

• Both extensions allow direct input of survey data

Secondary DataSecondary Data

• Large amount of data is now available• Always check for existing data before

creating it• Several groups of data exist

– Free data from the government– Government data available for a fee– Internet map servers– Commercial data– Data from other GIS users

Free Government DataFree Government Data

• Large amounts of data are available from– USGS– Census– NOAA

USGS DataUSGS Data

• DEM = Digital Elevation Model• NED = National Elevation Dataset• NHD = National Hydrography Dataset• DRG = Digital Raster Graphic• DLG = Digital Line Graph• DOQQ = Digital Ortho Quarter Quad• GNIS = Geographic Names Information System• LULC = Land Use Land Cover• NLCD = National Land Cover Data

DEMDEM• Available in Several Resolutions

– 3-arc-second • 1:250,000 Intended scale• Approximately 90m Cell size

– 2-arc-second• 35% of US coverage complete• 100% for New Mexico• 1:100,000 intended scale• Approximately 60m cell size

• 30m DEM– 1:24,000 intended scale– Production stopped in favor of 10m DEMs

• 10m DEM– 1:24,000 intended scale– Complete for New Mexico

Problems with USGS DEMsProblems with USGS DEMs

• Created by contractors with different standards

• Map Projection and units can very

• Can have gaps between adjacent DEMs– Fix by filling from a lower resolution DEM– Fix by averaging adjacent cells– Use NED instead

NEDNED

• Created from the 30m and 10m DEMs

• No Gaps, Units are standardized

• 100% coverage for the US

NHD http://nhd.usgs.govNHD http://nhd.usgs.gov

• National Hydrography Data Set• Contains information about naturally occurring and

constructed bodies of water• Has links to EPA RC3 river reach files• Has links to GNIS• Is setup for network modeling• Two resolutions are available

– 24k In progress– 100k Complete for New Mexico

• Files are being reformatted from Coverages to Geodatabases

DRGDRG

• Scans of the USGS Topographic Maps

• Scanned at 250 dpi or greater and resampled back to 250 dpi

• Earlier maps may be at a lower resolution

• Useful as base maps

USGS DRG Color Palette

Digital Number Color Red Green Blue

0 Black 0 0 0 1 White 255 255

2552 Blue 0 151

164 3 Red 203 0

23 4 Brown 131 66

37 5 Green 201 234

157 6 Purple 137

51 128 7 Yellow 255

234 0 8 Light Blue 167 226

2269 Light Red 255 184

184 10 Light Purple 218 179

214 11 Light Grey 209 209

209 12 Light Brown 207 164

142

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G

F

E

D

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B

12345678

O34106A1

O34106D4

O34106H8

35°

107°

DLGDLG

• http://edc.usgs.gov/products/map/dlg.html

Layer Feature Type

Public Land Survey System (PLSS) Township, range, and section lines

Boundaries State, county, city, and other national and State lands such as forests and parks

Transportation Roads and trails, railroads, pipelines and transmission lines

Hydrography Flowing water, standing water, and wetlands

Hypsography Contours and supplementary spot elevations

Non-vegetative features Glacial moraine, lava, sand, and gravel

Survey control and markers Horizontal and vertical monuments (third order or better)

Manmade features Cultural features, such as building, not collected in other data categories

Vegetative surface cover Woods, scrub, orchards, and vineyards

Large-Scale (7.5-minute) DLGsLarge-Scale (7.5-minute) DLGs

1. Large-Scale (7.5-minute) DLGs correspond to the USGS 1:20,000-, 1:24,000-, and 1:25,000-scale topographic quadrangle maps. They are primarily cast to the Universal Transverse Mercator (UTM) projection system, but some are cast to the State Plane coordinate system. They are referenced to either the North American Datum (NAD) of 1927 (NAD27) or the NAD of 1983 (NAD83). The files are available in Optional and Spatial Data Transfer Standard (SDTS) format. Optional format is distributed on CD-ROM, DVD, 8-mm tape, and File Transfer Protocol (FTP). SDTS format is distributed via FTP download.

Intermediate-Scale (1:100,000-scale)Intermediate-Scale (1:100,000-scale) DLG DLG

• Individual 1:100,000-Scale DLGs are sold in 30- by 30-minute units that correspond to the east or west half of USGS 30- by 60-minute topographic quadrangle maps. Each 30-minute unit is produced and distributed as four 15- by 15-minute cells. They are cast to the UTM projection system and are referenced to either NAD27 or NAD83. The files are available in Optional and SDTS format. Both formats are distributed on CD-ROM, DVD, 8-mm tape, and via FTP download.

2. Intermediate-Scale (1:100,000-scale) DLGs are derived from USGS 30- by 60-minute quadrangle maps. The following products are available:

• 1:100,000-Scale Hydrography and Transportation CD contains 30- by 60-minute quadrangles for the hydrography and transportation layers only. Fourteen sectional regions in the United States covering the conterminous 48 States and Hawaii are available. Each 30-minute unit is distributed as four 15- by 15-minute cells. They are cast to the UTM projection system and are referenced to either NAD27 or NAD83. Available in Optional format and distributed on CD-ROM.

Small-Scale (1,2,000,000-scale)Small-Scale (1,2,000,000-scale) DLGs DLGs

3. Small-Scale (1,2,000,000-scale) DLGs are derived from the USGS sectional maps from the U.S. National Atlas. The following products are available:

• 1:2,000,000 State DLGs (Current Data) contain files that date between 1990 and 1994. The files are organized on a state-by-state basis, and include the conterminous U.S. and Hawaii. Alaska is not available. They are cast to Albers Equal-Area conic projection. 1:2,000,000 State DLGs are available in Optional and SDTS format. Optional format is distributed on CD-ROM. SDTS format is distributed via FTP download.

• 1:2,000,000 Section DLGs (Historical Data) contain files that date between 1973 and 1980. The U.S. and Hawaii are divided into 21 regional sections. The files are distributed on CD-ROM and each CD will include Optional, Standard, and Graphic formats. Optional format is cast to the Albers Equal-Area conic projection. Standard format is cast to the Cartesian coordinate system. Graphic format is expressed in geographic coordinates (latitude/longitude).

GNIS http://gnis.usgs.govGNIS http://gnis.usgs.gov

• Geographic Names Information SystemAbout GNISThe Geographic Names Information System (GNIS), developed by the USGS in cooperation with the U.S. Board on Geographic Names (BGN), contains information about almost 2 million physical and cultural geographic features in the United States and its territories. The Federally recognized name of each feature described in the data base is identified, and references are made to a feature's location by State, county, and geographic coordinates. The GNIS is our Nation's official repository of domestic geographic names information. The GNIS also contains information on geographic names in Antarctica which are approved by the BGN for use by the Federal Government. Information about foreign geographic feature names can be obtained from the GEOnet Names Server (GNS), developed and maintained by the National Imagery and Mapping Agency.

LULCLULC• http://edc.usgs.gov/products/landcover/lulc.html

Product DescriptionLand Use and Land Cover (LULC) data consists of historical land use and land cover classification data that was based primarily on the manual interpretation of 1970's and 1980's aerial photography. Secondary sources included land use maps and surveys. There are 21 possible categories of cover type. Along with the LULC files, associated maps are included which provide additional information on political units, hydrologic units, census county subdivisions, and Federal and State land ownership. LULC data is available for the conterminous U.S. and Hawaii, but coverage is not complete for all areas. The data is based on 1:100,000- and 1:250,000-scale USGS topographic quadrangles.

All LULC files are cast to the Universal Transverse Mercator (UTM) projection, and referenced to the North American Datum of 1983 (NAD83). The files are available in GIRAS (Geographic Information Retrieval and Analysis System) or CTG (Composite Theme Grid) format. The spatial resolution for all LULC files will depend on the format and feature type. Files in GIRAS format will have a minimum polygon area of 10 acres (4 hectares) with a minimum width of 660 feet (200 meters) for manmade features. Non-urban or natural features have a minimum polygon area of 40 acres (16 hectares) with a minimum width of 1320 feet (400 meters). Files in CTG format will have a resolution of 30 meters.

All LULC data is available via FTP download only. LULC data in ArcInfo export format is also available from the EPA (1:250,000 scale only).

NLCDNLCD• http://landcover.usgs.gov/prodescription.aspProduct Description:Derived from the early to mid-1990s Landsat Thematic Mapper satellite data, the National Land Cover Data (NLCD) is a 21-class land cover classification scheme applied consistently over the United States. The spatial resolution of the data is 30 meters and mapped in the Albers Conic Equal Area projection, NAD 83. The NLCD are provided on a state-by-state basis. The state data sets were cut out from larger "regional" data sets that are mosaics of Landsat TM scenes. At this time, all of the NLCD state files are available for free download as 8-bit binary files and some states are also available on CD-ROM as a Geo-TIFF. The TM multi-band mosaics were processed using an unsupervised clustering algorithm. Both leaves-off and leaves-on data sets were analyzed. The resulting clusters were then labeled using aerial photography and ground observations. Clusters that represented more than one land cover category were also identified and, using various ancillary data sets, models developed to split the confused clusters into the correct land cover categories. Click here for a more detailed discussion of the mapping and classification procedures. A hierarchical land cover classification scheme of 21 classes was developed and applied in a consistent manner across the entire United States. The classification scheme follows:

21-Class National Land Cover Data Key:

NOTE - All Classes May NOT Be Represented in a specific state data set. The class number represents the digital value of the class in the data set (for a detailed description of each class, see any state "readme" file).

U.S. Census BureauU.S. Census Bureau

• TIGER = Topologically Integrated Geographic Encoding and Referencing

• Census – Block– Group– Track

TIGERTIGER

• Topologically Integrated Geographic Encoding and Referencing

• http://www.census.gov/geo/www/tiger/overview.html• What is TIGER®?• The term TIGER® comes from the acronym Topologically Integrated Geographic

Encoding and Referencing which is the name for the system and digital database developed at the U.S. Census Bureau to support its mapping needs for the Decennial Census and other Bureau programs.

• The design of the TIGER® database adapts the theories of topology, graph theory, and associated fields of mathematics to provide a disciplined, mathematical description for the geographic structure of the United States and its territories. The topological structure of the TIGER® data base defines the location and relationship of streets, rivers, railroads, and other features to each other and to the numerous geographic entities for which the Census Bureau tabulates data from its censuses and sample surveys. It is designed to assure no duplication of these features or

areas.

Census Block, Group, and TrackCensus Block, Group, and Track

• census block - A geographic area bounded by visible and/or invisible features shown on a map prepared by the U.S. Census Bureau. A block is the smallest geographic entity for which the Census Bureau tabulates decennial census data. See block boundary, block number.

• block group (BG) - A statistical subdivision of a census tract (or, prior to Census 2000, a block numbering area). A BG consists of all tabulation blocks whose numbers begin with the same digit in a census tract. For example, for Census 2000, BG 3 within a census tract includes all blocks numbered from 3000 to 3999. (A few BGs consist of a single block.) BGs generally contain between 300 and 3,000 people, with an optimum size of 1,500 people. The BG is the lowest-level geographic entity for which the U.S. Census Bureau tabulates sample data from a decennial census. See tribal block group.

• census tract - A small, relatively permanent statistical subdivision of a county or statistically equivalent entity, delineated for data presentation purposes by a local group of census data users or the geographic staff of a regional census center in accordance with U.S. Census Bureau guidelines. Designed to be relatively homogeneous units with respect to population characteristics, economic status, and living conditions at the time they are established, census tracts generally contain between 1,000 and 8,000 people, with an optimum size of 4,000 people. Census tract boundaries are delineated with the intention of being stable over many decades, so they generally follow relatively permanent visible features. However, they may follow governmental unit boundaries and other invisible features in some instances; the boundary of a state or county (or statistically equivalent entity) is always a census tract boundary. When data are provided for American Indian entities, the boundary of a federally recognized American Indian reservation and off-reservation trust land is always the boundary of a tribal census tract. See block numbering area, tribal census tract.

NOAANOAA

• Shoreline Data– http://www.csc.noaa.gov/shoreline/data.html

• Estuarine Bathymetry– http://sposerver.nos.noaa.gov/bathy/

• NCDC = National Climatic Data Center– NCDC is the world's largest active archive of

weather data– http://www.ncdc.noaa.gov/oa/ncdc.html

NCDCNCDC

• NCDC archives 99 percent of all NOAA data, including over 320 million paper records; 2.5 million microfiche records; over 1.2 petabytes of digital data residing in a mass storage environment. NCDC has satellite weather images back to 1960. NCDC annually publishes over 1.2 million copies of climate publications that are sent to individual users and 33,000 subscribers. NCDC maintains over 500 digital data sets, receives almost 2,000,000 requests each year, and records over 100 million hits per year on the website.

New Mexico DataNew Mexico Data• rgis.unm.edu

– New Mexico Clearinghouse• Office of the State Engineer

– http://www.ose.state.nm.us/water-info/gis-data/index.html• W.A.T.E.R.S

– Water Well Data• Declared Ground Water Basins• The Espanola Basin Technical Advisory Group

• PRRC– GO-TECH– http://octane.nmt.edu/

• Oil and Gas leases• NCRDS = National Coal Resources Data System

• NMBG&MR– http://geoinfo.nmt.edu/statemap/quads/quad_index.html– pdf file of maps in the statemap program– We have ArcGIS for some of these quads

GIS Data WebsitesGIS Data Websites

• http://seamless.usgs.gov/viewer.htm

• http://gisdata.usgs.gov

• http://edcsns17.cr.usgs.gov/EarthExplorer/

• http://data.geocomm.com/

Internet Map ServersInternet Map Servers

• Image Server– A server generate an image of a map and

sends it to a browser or plugin– http://ginsberg.nmt.edu/website/EPSCoR-Hyd/viewer.htm

• Feature Servers– A server selects the features you need and

sends them to you client– The Client can be ArcMap, ArcReader, or a

custom viewer

Commercial DataCommercial Data

• Many Data Products are repackaged free data

• Street Map and address data– GDT Dynamap is a very popular choice

• Remote Sensing Data Sets– Spot– LIDAR– US Satellites

Ask Other GIS UsersAsk Other GIS Users

• NMGIC New Mexico Geographic Information council