Remote Sensing Image Acquisition Supplement to Lecture 1 material prepared by R Lathrop 9 99 updated 8 03 includes slides previously prepared by S Madry and C Colvard Readings ERDAS Field Guide 5th Ed Ch 1 3 56 82 Digital 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 sensor Early Kite system acquired attempts aerial photos of the great San Francisco earthquake and fire Pigeon cameras The development of aircraft World Wars I and II Aerial Cameras A large format oblique camera Keystone s Wild RC10 mapping camera Aerial Black White photos single panchromatic layer Color 3 layers B G R Color IR 3 layers G R NIR USGS Aerial Photo Products Aerial Products Description National 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 html Aerial 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 html Aerial 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 gov Analog 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 camera Airborne Digital Imaging Systems Aircraft 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 html Digital 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 time Space borne Remote Sensing Still Emerging Technology Pro GIS ready fast turn around acquisition time of 5 minutes gives equal solar illumination shadows long term archive of repeat imagery for change detection Con Significant investment in infrastructure Less flexibility in acquisition Remote Sensing Satellites in Space How do they get there http visibleearth nasa gov cgi bin viewrecord 492 MODIS Terra Launches http visibleearth nasa gov cgi bin viewrecord 135 Types of satellite orbits Geostationary Polar 700 900 km 35 800 km Polar Orbitting Satellite http visibleearth nasa gov cgi bin viewrecord 134 Geostationary vs polar orbiting sensors Geostationary sensors orbit with the earth continually viewing the same hemispheric area Polar orbiters continually view new areas of the earth as the planet rotates underneath the sensor Keeps the same general solar time as it cross the equator on each orbit called sun synchronous Polar orbit Many 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 each AVHRR Thermal AVHRR provides water temperature data 3 bands in TIR Gulf Stream Remote 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 years For more info and images go to http daac gsfc nasa gov CAMPAIGN DOCS BRS SRVR avh rrbrs main html Global 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 productivity Remote 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 B IO GLBDST Images html You can either browse through individual images or watch an animation First click on the Global 1 degree 1986 NDVI Climate Data Set 1 5 MB Quicktime animation Open it and click on the button You can go more slowly by clicking on the button Remote Sensing of the Earth Clues to a Living Planet First click on the Global 1 degree 1986 NDVI Climate Data Set 1 5 MB Quicktime animation Open it and click on the button Watch closely can you observe the Green Wave in the northern hemisphere What about the Brown Wave Now look at the southern hemisphere What do you observe Can you see the Green Wave http daac gsfc nasa gov CAMPAIGN DOCS LAND BIO GLBDST Images html Remote Sensing of the Earth Clues to a Living Planet Now take a look at the Northern hemisphere in greater detail Click on the North America 1986 NDVI 750K quicktime Animation Can you find where you live How long does it stay green Compare Florida with Maine or Minnesota North America Close up http daac gsfc nasa gov CAMPAIGN DOC S LAND BIO GLBDST Images html Remote Sensing of the Earth Clues to a Living Planet To access more recently acquired AVHRR imagery go to the National Oceanographic Atmospheric Administration NOAA Satellite Active Archive http www saa noaa gov After a picture perfect launch into space December 1999 Terra Began releasing images April 2000 Terra includes MODIS a 2nd generation AVHRR like instrument with a number of potential applications in regional to global scale environmental monitoring of the land ocean and atmosphere Also includes ASTER CERES MISR and MOPITT For more info go to http terra nasa gov MODIS TERRA in Orbit http