more remote sensing today- - announcements - review of few concepts - measurements from imagery -...

More Remote SensingMore Remote Sensing

Today-Today-

- announcementsannouncements-Review of few conceptsReview of few concepts

-Measurements from imageryMeasurements from imagery-Satellites and ScannersSatellites and Scanners

►http://ngs.woc.noaa.gov/katrina/http://ngs.woc.noaa.gov/katrina/

AnnouncementsAnnouncements

►Should read chapter 6 for Thursday. Should read chapter 6 for Thursday. Not on Syllabus!Not on Syllabus!

►Bring rulers to class on Thursday… if Bring rulers to class on Thursday… if you got one.you got one.

Last lecture we talked Last lecture we talked about…about…

►Remote sensingRemote sensing►Map interpretationMap interpretation►Geographical data acquisition, Geographical data acquisition,

management, and analysismanagement, and analysis► Introduction to Geographic Information Introduction to Geographic Information

SystemsSystems►Map productionMap production

Remote SensingRemote Sensing

►……is the gathering of information by is the gathering of information by means of a sensor that is not in means of a sensor that is not in contact with the object being contact with the object being detected.detected.

Nature of EM radiation

Atmospheric windowsAtmospheric windows


►Types of sensorsTypes of sensors ActiveActive PassivePassive


►See page 254 in CampbellSee page 254 in Campbell FilmFilm

►PanchromaticPanchromatic►ColorColor►False Color IRFalse Color IR

SensorsSensors►Narrow-band Narrow-band ►Multispectral devicesMultispectral devices


►How the image is taken..How the image is taken.. VerticalVertical High-oblique (with horizon)High-oblique (with horizon) Low-oblique (without horizon)Low-oblique (without horizon)


► verticalvertical


► obliqueoblique


► Why use obliques??Why use obliques??


►Summary of a few things…Summary of a few things… Remote sensing instruments can be Remote sensing instruments can be

divided in many different ways…divided in many different ways…►Active / passiveActive / passive►Film / sensorFilm / sensor►Narrow band / multispectralNarrow band / multispectral►Angle of photo / scanAngle of photo / scan


►Aerial Photos…Aerial Photos… how they are made… p. 258how they are made… p. 258 Planimetric Shift… p. 260Planimetric Shift… p. 260

OK, so… some new stuff…OK, so… some new stuff…

►Scale…..Scale….. Large and smallLarge and small

ScaleScale

►Large scale is local Large scale is local

►Small scale is globalSmall scale is global

ScaleScale

►Word scalesWord scales►Representative fractionRepresentative fraction►GraphicGraphic

ScaleScale

►1:24,000 topos1:24,000 topos

►Brits do Brits do word scaleword scale.. ..

1 inch represents one mile 1 inch represents one mile

A.K.A. 1 : 63,360A.K.A. 1 : 63,360

Graphic scaleGraphic scale

Finding scale on an imageFinding scale on an image

►Find something on photo with a known Find something on photo with a known sizesize

►Compare to a map or other photo with Compare to a map or other photo with a known scale.a known scale.

Measuring stuff on an imageMeasuring stuff on an image- Photogrammetry - - Photogrammetry -

►LinearLinear Dimensional analysisDimensional analysis



►AreaArea


►But what if they are squiggly But what if they are squiggly features???features???


►AreaArea



►AreaArea

►HeightHeight ShadowsShadows Planimetric shiftPlanimetric shift

See photo in Remote Sensing See photo in Remote Sensing bookbook

►Video projectorVideo projector

Measuring stuff on an imageMeasuring stuff on an image- Photogrammetry – - Photogrammetry –

► What about the effects of mountains and terrain on What about the effects of mountains and terrain on measurements??measurements??

► LinearLinear Dimensional analysisDimensional analysis

► AreaArea

► HeightHeight ShadowsShadows Planimetric shiftPlanimetric shift

Scanners and satellite Scanners and satellite imageryimagery

►How scanners work…. As opposed to How scanners work…. As opposed to photosphotos

►PixelsPixels►Often 256 values 0 – 255 levels of Often 256 values 0 – 255 levels of

detectiondetection►MultispectralMultispectral

Bands covered… 3 in visible, near IR and Far Bands covered… 3 in visible, near IR and Far IRIR

Also radar and microwave (active systems)Also radar and microwave (active systems)

►A brief history of satellitesA brief history of satellites►1972 Landsat.1972 Landsat.

1-4 no longer work, 6 bit it. 5 and 7 still 1-4 no longer work, 6 bit it. 5 and 7 still workingworking

Cover same spot on earth about every 16 Cover same spot on earth about every 16 daysdays

““Whisk broom scanner” Whisk broom scanner” Multispectral scanner and thematic Multispectral scanner and thematic

mappermapper

Start here…..Start here…..Scanners and satellite imageryScanners and satellite imagery


►Multispectral scannerMultispectral scanner 79 by 79 resolution 79 by 79 resolution See page 272 (top) for bands coveredSee page 272 (top) for bands covered

► The MSS can simulate rather crude spectral signatures. Bands 4, 5, and 6 each have a The MSS can simulate rather crude spectral signatures. Bands 4, 5, and 6 each have a bandwidth of 0.1 µm; and band 7's width is 0.3 µm. We represent band responses by bars bandwidth of 0.1 µm; and band 7's width is 0.3 µm. We represent band responses by bars in a histogram-like plot, in which the height of the bar signifies the relative reflectances in a histogram-like plot, in which the height of the bar signifies the relative reflectances

averaged for all wavelengths within the bandwidth interval..averaged for all wavelengths within the bandwidth interval.. From…http://rst.gsfc.nasa.gov/Intro/Part2_18.htmlFrom…http://rst.gsfc.nasa.gov/Intro/Part2_18.html

From From http://www.grid.unep.ch/proser/remotesens/iraq.php. Landsat image: MSS . Landsat image: MSS Bands 4, 2 and 1, taken on Bands 4, 2 and 1, taken on 16 February 1973, 14 16 February 1973, 14 February 1975 and 27 May February 1975 and 27 May 1976.1976.


►Multispectral scannerMultispectral scanner 79 by 79 resolution 79 by 79 resolution See page 272 (top) for bands coveredSee page 272 (top) for bands covered

►thematic mapperthematic mapper 30 x 30 resolution (thermal – 120 or 60)30 x 30 resolution (thermal – 120 or 60) See page 273 for bands coveredSee page 273 for bands covered


►Resolution Resolution Object needs to be 2x resolution to be Object needs to be 2x resolution to be

seen (reliably)seen (reliably)

► From From http://www.grid.unehttp://www.grid.unep.ch/proser/remotesp.ch/proser/remotesens/iraq.phpens/iraq.php. Landsat image: . Landsat image: ETM Bands 4, 3 and ETM Bands 4, 3 and 2, taken on 26 2, taken on 26 March and 4 May March and 4 May 2000. 2000.

Atmospheric windowsAtmospheric windows

►TM imageTM image►Bands 2, 3, 4Bands 2, 3, 4►Displayed Displayed

blue, green, blue, green, redred

► 25-Meter 25-Meter MultispectraL, Landsat MultispectraL, Landsat TM, Bands 7,4,3 TM, Bands 7,4,3 (RGB), Acquired (RGB), Acquired February 13, 1989. In February 13, 1989. In this image of Hong this image of Hong Kong, vegetation Kong, vegetation appears in green, bare appears in green, bare soil is reddish purple, soil is reddish purple, and urban features and urban features are purple and white. are purple and white. This particular band This particular band combination easily combination easily distinguishes distinguishes water/land boundaries water/land boundaries because water bodies because water bodies (shown in black) (shown in black) contrast strongly with contrast strongly with colorful land features. colorful land features.

► From From http://landsat.gsfc.nashttp://landsat.gsfc.nasa.gov/images/gallery.a.gov/images/gallery.htmlhtml

►http://www.siskiyous.edu/shasta/map/http://www.siskiyous.edu/shasta/map/sat/sat/


►SPOTSPOT ‘‘push-broom’ scannerpush-broom’ scanner 3 visible and near IR3 visible and near IR 20 meter multispect and 10 meter single20 meter multispect and 10 meter single Fly-over same spot each 20 days (apx) Fly-over same spot each 20 days (apx) Can be pointed away from vertical. Uses?Can be pointed away from vertical. Uses?

►Stereopairs, more frequent observationsStereopairs, more frequent observations


► IKONOSIKONOS 1 meter (page 274 in book)1 meter (page 274 in book)

►ActiveActive Radar and microwaveRadar and microwave

►MilitaryMilitary ????????????


►Contrast stretching and edge Contrast stretching and edge enhancementenhancement

(page. 276)(page. 276)

To Summarize……To Summarize……


►Summary of a few things…Summary of a few things… Remote sensing instruments can be Remote sensing instruments can be

divided in many different ways…divided in many different ways…►Active / passiveActive / passive►Film / sensorFilm / sensor►Narrow band / multispectralNarrow band / multispectral►Angle of photo / scanAngle of photo / scan

PhotogrammetryPhotogrammetry

►SummarySummary ScaleScale Measurements, linear, area, heightMeasurements, linear, area, height Dimensional analysisDimensional analysis Effects of topographyEffects of topography


►SummarySummary Pixels and scannersPixels and scanners MSS, TM, SPOT, etcMSS, TM, SPOT, etc ResolutionResolution BandsBands ‘‘false color’false color’ ComparisonsComparisons Image enhancementImage enhancement

more remote sensing today- - announcements - review of few concepts - measurements from imagery -...

Documents

horizon slide

small slide

govkatrina slide

global slide

remote sensing oblique

remote sensing vertical

graphic scale slide

atmospheric windows