Landsat Studying the Earth from Space Ratko Jagodic University of Illinois at Chicago

Ratko Jagodic What is Landsat? Developed by NASA to take pictures of Earth’s continental and coastal surfaces Developed by NASA to take pictures of Earth’s continental and coastal surfaces Satellites in space gathering, storing and distributing images Satellites in space gathering, storing and distributing images Started in 1972 Started in satellites so far: 7 satellites so far: Landsat 6 never made it Landsat 6 never made it  Landsat 5 still operational (20 years!)Landsat 5 still operational (20 years!) Landsat 7 most recent oneLandsat 7 most recent one

University of Illinois at Chicago Ratko Jagodic Motivation Tracking global changes: Tracking global changes: environmental monitoringenvironmental monitoring geological and hydrological analysisgeological and hydrological analysis land use classification and mappingland use classification and mapping coastal resourcescoastal resources land surface analysisland surface analysis

University of Illinois at Chicago Ratko Jagodic Landsat 7 Launched 1999 Launched 1999 Visible and IR frequency recordings Visible and IR frequency recordings Zoom - Higher ground resolution (30 m) Zoom - Higher ground resolution (30 m) Covers Earth in 16 days, orbits in 99 min Covers Earth in 16 days, orbits in 99 min 365 GB solid state storage 365 GB solid state storage Many receiving stations around the world Many receiving stations around the world

University of Illinois at Chicago Ratko Jagodic How it works Passive remote sensing Passive remote sensing Detecting EM radiation (IR + Visible) emitted or reflected from Earth Detecting EM radiation (IR + Visible) emitted or reflected from Earth Enhanced Thematic Mapper Plus (ETM+) Enhanced Thematic Mapper Plus (ETM+) Not a photograph but electronic radiation detection Not a photograph but electronic radiation detection

University of Illinois at Chicago Ratko Jagodic ETM+ EM radiation detected in 8 distinct bands (3 visible, 3 IR, thermal IR and panchromatic) EM radiation detected in 8 distinct bands (3 visible, 3 IR, thermal IR and panchromatic)

University of Illinois at Chicago Ratko Jagodic ETM+ (contd.) 8 detectors (1/band) on 2 focal planes (cold and primary) 8 detectors (1/band) on 2 focal planes (cold and primary)

University of Illinois at Chicago Ratko Jagodic Scanning Process Orbits in North/South direction (99min) Orbits in North/South direction (99min) Sweeps a 185 km wide track Sweeps a 185 km wide track Scans across track in zigzag motion Scans across track in zigzag motion

University of Illinois at Chicago Ratko Jagodic Data Processing Across tracks are digitized Across tracks are digitized Then composed into 185 X 170km scenes (stored or transmitted real time) Then composed into 185 X 170km scenes (stored or transmitted real time)

University of Illinois at Chicago Ratko Jagodic Image Processing Level 0 Reformatted (L0R) - raw data Level 0 Reformatted (L0R) - raw data Level 1 Radiometrically Corrected (L1R) Level 1 Radiometrically Corrected (L1R) Level 1 Geometrically Corrected (L1G) Level 1 Geometrically Corrected (L1G)

University of Illinois at Chicago Ratko Jagodic Examples Deforestation in Amazon (1975 vs. 1992) Deforestation in Amazon (1975 vs. 1992)

University of Illinois at Chicago Ratko Jagodic Examples Lake Chad in West Africa (1963 vs. 1997) Lake Chad in West Africa (1963 vs. 1997)

University of Illinois at Chicago Ratko Jagodic Examples Las Vegas (1972 vs. 1992) Las Vegas (1972 vs. 1992)

University of Illinois at Chicago Ratko Jagodic Examples Venice (imaging shallow waters) Venice (imaging shallow waters)

University of Illinois at Chicago Ratko Jagodic References USGS Landsat Project USGS Landsat Project Landsat 7 Page Landsat 7 Page NASA Landsat 7 Page NASA Landsat 7 Page

University of Illinois at Chicago Ratko Jagodic