Sources of Geographic InformationThe Landsat Series of SatellitesLandsat Platforms and their SensorsThematic Mapper BandsLandsat 1, 2, and 3Landsat 4 and 5Landsat (6 and) 7Landsat OrbitsLandsat Temporal ResolutionLandsat TM Swath Width‘Wiskbroom’ SensorsThe Thematic Mapper SensorScan Line Corrector Failure aboard Landsat 7Using Landsat to Study Land Use ChangeThe SPOT Series of SatellitesSPOT CharacteristicsSPOT Platforms‘Pushbroom’ SensorsSPOT Sensor CharacteristicsSPOT SatellitePointable SPOT SensorsSPOT Operational CapabilitySPOT 5 HRS SensorSPOT 5 HRS SensorIkonosIkonos Image - Athens Olympic Sports ComplexQuickbirdQuickbird Image - Athens Olympic Sports ComplexDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005•Data properties: Spatial data, i.e. data that are associated with geographic locations•Data format: digital (analog data for traditional paper maps)•Data Inputs:•sampled from the real world•digitizing from paper maps•produced by government agencies, e.g. census bureau, USGS, USFS, state government, etc.•space or airborne remote sensing(NASA, NOAA, commercial, etc.)Approximately 80% of the duration of many large scale GIS projects is concerned with data input and managementSources of Geographic InformationDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005•While early applications of remote sensing were developed for military use, those technologies are now of benefit to society in many other applications, including environmental research•On July 23, 1972, the first remote sensing satellite designed to collect satellite imagery throughout the globe for research purposes -- the Earth Resource Satellite -- was launched. This satellite was later renamed Landsat. The Landsat series of satellites continues to be used today (now up to Landsat 7)•While successive satellites in the series had more advanced sensors aboard, an effort was made to maintain some continuityin both the sensors’ characteristics (e.g. their spatial, spectral, temporal, and radiometric resolutions) so that data collected from sensors aboard new platforms could be compared reasonably to older dataThe Landsat Series of SatellitesDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Satellite Launched Decom. RBV MSS TM Orbit Info.Landsat-1 23 Jul 1972 6 Jan 1978 1-3 4-7 none 18d/900kmLandsat-2 22 Jan 1975 25 Feb 1982 1-3 4-7 none 18d/900kmLandsat-3 5 Mar 1978 31 Mar 1983 A-D 4-8 none 18d/900kmLandsat-4 16 Jul 1982 -- none 1-4 1-7 16d/705kmLandsat-5 2 Mar 1984 -- none 1-4 1-7 16d/705kmLandsat-6 5 Oct 1993 Launch Failure none none ETM 16d/705kmLandsat-7 15 Apr 1999 -- none none ETM+ 16d/705kmRBV: Return Beam Vidicon {Blue, Green, Red}@~40mMSS: Multi-spectral Scanner {Green, Red, NIR1, NIR2)@~80mTM: Thematic Mapper {Blue, Green, Red, NIR, IR1, IR2}@~30m, TIR@120mETM: Thematic Mapper {Blue, Green, Red, NIR, IR1, IR2}@~30m, TIR@60mLandsat Platforms and their SensorsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Spectral Bands of Landsat Thematic Mapper Sensorshttp://www.satelliteimpressions.com/landsat.html Thematic Mapper BandsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Landsat 1, 2, and 3Aronoff, S. 1989. Geographic Information Systems: A Management Perspective. WDL Publications, Ottawa, Ontario, Canada, p. 78.RBVReturn Beam Vidicon~40m pixelsMSSMulti-Spectral Scanner~80m pixelsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Landsat 4 and 5Aronoff, S. 1989. Geographic Information Systems: A Management Perspective. WDL Publications, Ottawa, Ontario, Canada, p. 79.MSSMulti-Spectral Scanner~80m pixelsTMThematic Mapper~30m pixelsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Landsat (6 and) 7ETM+ Enhanced Thematic Mapper Plus ~30m pixelsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005•Landsat satellites’ orbits are designed to be sun-synchronous orbits, meaning that the satellites always cross the Equator at precisely the same local time (~10:00 am)•In this way, images collected of different parts of the globe are collected under as similar illumination conditions as possibleLandsat OrbitsDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Landsat Temporal ResolutionDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005185 kmField of View175kmsceneLandsatSatellite ground track705kmSpatial ResolutionPixel size=(30x30m)Landsat TM Swath WidthDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005‘Wiskbroom’ SensorsAronoff, S. 1989. Geographic Information Systems: A Management Perspective. WDL Publications, Ottawa, Ontario, Canada, p. 72.David Tenenbaum – GEOG 070 – UNC-CH Spring 2005The Thematic Mapper Sensorhttp://ltpwww.gsfc.nasa.gov/IAS/handbook/handbook_htmls/chapter13/htmls/slc.html ^David Tenenbaum – GEOG 070 – UNC-CH Spring 2005Scan Line Corrector Failure aboard Landsat 7•On May 31, 2003, the scan line corrector in the Enhanced Thematic Mapper plus sensor failedDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Landsat 5 TM image on Dec 10,1988 of the Shenzhen Special Econ.Zone, China (RGB=432)Landsat 5 TM image on Dec 30,1995 of the Shenzhen Special Econ.Zone, China (RGB=432)Using Landsat to Study Land Use ChangeDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005•The United States’ work with the Landsat series of satellites is not the sole example of a series of space-based satellite platforms that were developed to house multi-spectral scanning sensors designed to image the whole of the globe•While the Landsat satellites in the 1970’s were certainly the pioneering effort of this type, France soon followed suit with its SPOT (Systeme Pour L’Observation de la Terre -translation: System for Earth Observation) program•SPOT 1 was launched in early 1986, and used some slightly different approaches to achieve higher spatial resolutionsand flexibility in image targeting which the Landsat program did not achieveThe SPOT Series of SatellitesDavid Tenenbaum – GEOG 070 – UNC-CH Spring 2005Launch DatesSPOT 1: February 22, 1986SPOT 2: January 22, 1990SPOT 3: September 26, 1993SPOT 4: March 24, 1998SPOT 5: May 3, 2002HRV imaging instruments: SPOT 1, 2 and 3Spectral bands: Spatial resolution swath width0.5-0.59 (green) 20x20 m