Remote Sensing Image AcquisitionDigital Image AcquisitionEarly attemptsAerial CamerasAerial photosUSGS Aerial Photo ProductsAerial Photographic SourcesSlide 8Analog Image DigitizationAirborne Digital Imaging SystemsSpace-borne Remote SensingRemote Sensing Satellites in Space: How do they get there?MODIS Terra LaunchesTypes of satellite orbitsPolar Orbitting SatelliteGeostationary vs. polar orbiting sensorsMany different systems - which to choose?Slide 18AVHRRRemote Sensing of the Earth: Clues to a Living PlanetGlobal AVHRR compositeSlide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28MODIS TERRA in OrbitSlide 30Slide 31Slide 32ERTS-1Landsat MSS bands 4 and 5Landsat MSS bands 6 and 7MSS color compositeLandsat 4-5 Thematic Mapper (TM)Cross-track scanning systemLandsat TM-7 bands-8 bit dataSpectral wavebands of Landsat TMLandsat TM: each waveband provides different information about earth surface featuresThermal imagery-temperatureSlide 43Commercialization of LandsatLandsat 7Slide 46Slide 47Slide 48Slide 49SPOT before launchSPOT ground stationsSPOT 4 1st images taken March 31, 1998Polar Sun synchronous orbitSPOT has steerable mirrorStereo imagingIndian Remote Sensing (IRS) satelliteSpace Imaging IKONOSSlide 58Slide 59Slide 60Slide 61QuickbirdSlide 64Slide 65Good Bye from Planet EarthRemote Sensing Image AcquisitionSupplement to Lecture 1material prepared by R. Lathrop 9/99 updated 8/03includes slides previously prepared by S. Madry and C. ColvardReadings:ERDAS Field Guide 5th Ed. Ch 1, 3:56-82Digital Image Acquisition•Digitization of analog aerial photography, can be very useful for historical studies and/or for high spatial resolution needs•Direct acquisition using some form of digital imaging sensorEarly attempts•Kite system acquired aerial photos of the great San Francisco earthquake and fire•Pigeon cameras•The development of aircraft•World Wars I and IIAerial CamerasA large format oblique cameraKeystone’s Wild RC-10 mapping cameraAerial photos•Black & White - single panchromatic layer•Color: 3 layers B-G-R•Color IR: 3 layers G-R-NIRUSGS Aerial Photo ProductsAerial Products DescriptionNational Aerial Photography Program (NAPP) Recent,high-quality aerial photos covering the conterminous U.S. on five- to seven-year cycles (1987 - present).National High Altitude Photography (NHAP) High-altitude aerial photos for the conterminous U.S. (1980 - 1989).Digital Orthophoto Quadrangles (DOQs) Digital images of aerial photos which combine the image characteristics of the photo with the georeferenced qualities of a map (1987 - present).Space Acquired Photography Photos taken from the International Space Station (ISS), Shuttle, Skylab, Gemini, and Apollo missions (1965 - present). For more info: http://edc.usgs.gov/products/aerial.htmlAerial Photographic Sources•USDA: (since 1955): mainly PAN of 1:20,000-1:40,000. These photos are archived by the Aerial Photography Field Office http://www.fsa.usda.gov/dam/APFO/airfto.htm•National Archives and Records Administration archives older (pre- 1950’s) aerial photography http://www.nara.gov/research/ordering/mapordr.htmlAerial Photographic Sources•National Ocean Survey (NOS) coastal photography: (since 1945), color, scales of 1;10,000 - 1:50,000•The photos are used for a variety of geo-positioning applications, which include delineating the shoreline for Nautical Chart creation, measuring water depths, mapping seabed characteristics, and locating obstructions to marine and air navigation.•http://mapfinder.nos.noaa.govAnalog Image Digitization•Can take analog photography and turn into digital images•Scanning micro-densitometer•Linear array charge-coupled device e.g., flat-bed scanners•Area array charge-coupled device e.g., digital cameraAirborne Digital Imaging SystemsAircraft Scanners Digital imagery acquired from several multispectral scanners on board NASA ER-2, NASA C-130B, and NASA Learjet aircrafts (1982 - 1995).For more info: http://edcdaac.usgs.gov/airborne/air_scan.htmlDigital Cameras increasingly aerial imagery is being acquired through digital camera framing systems that can collect multispectral (VIS-NIR) imagery and be quickly corrected through GPS-based navigational systems to produce digital orthophotographic imagery in near-real timeSpace-borne Remote SensingStill Emerging TechnologyPro:•GIS ready•fast turn around•acquisition time of 5 minutes gives equal solar illumination, shadows•long term archive of repeat imagery for change detectionCon:•Significant investment in infrastructure•Less flexibility in acquisitionRemote Sensing Satellites in Space: How do they get there?http://visibleearth.nasa.gov/cgi-bin/viewrecord?492MODIS Terra Launcheshttp://visibleearth.nasa.gov/cgi-bin/viewrecord?135Types of satellite orbits•Geostationary Polar35,800 km700-900 kmPolar Orbitting Satellitehttp://visibleearth.nasa.gov/cgi-bin/viewrecord?134Geostationary vs. polar orbiting sensorsGeostationary sensors orbit with the earth continually viewing the same hemispheric areaPolar orbiters, continually view new areas of the earth as the planet rotates underneaththe sensor. Keeps the same general solar time as it cross the equator on each orbit - called sun synchronousPolar orbitMany different systems - which to choose?•AVHRR-Advanced Very High Resolution Radiometer•Polar orbit, coarse spatial resolution: 1 and 4 km cells, broad 2400 km ground swath width•2 operational now-1 day and 1 night pass for eachAVHRR•Thermal AVHRR provides water temperature data•3 bands in TIRGulf StreamRemote Sensing of the Earth: Clues to a Living Planet•Scientists at the NASA Goddard Space Flight Center have used the AVHRR to create maps of vegetation greenness for the entire globe•The NASA scientists have combined numbers of satellite images to create a composite picture of the earth at approximately biweekly intervals over a number of yearsFor more info and images, go to: http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/BRS_SRVR/avhrrbrs_main.htmlGlobal AVHRR composite•1 band in the Red: .58-.6 um•1 band in the NIR: .72-1.1 um•Vegetation Index to map vegetation amount and productivityRemote Sensing of the Earth: Clues to a Living Planet•You can access these images over the INTERNET•http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/LAND_BIO/GLBDST_Images.html•You can either browse through individual images or watch an animation•First, click on the Global 1 degree 1986 NDVI