Sensors Onboard Landsat PDF

Sensors Onboard LANDSAT  The first three LANDSAT satellites were identical and their payloads consisted of two optical instruments, a multispectral sensor (MultiSpectral Scanner or MSS)and a series of video cameras (Return Beam Vidicons or RBVs).  LANDSAT 1-3 altitude: 907-9...

Sensors Onboard LANDSAT  The first three LANDSAT satellites were identical and their payloads consisted of two optical instruments, a multispectral sensor (MultiSpectral Scanner or MSS)and a series of video cameras (Return Beam Vidicons or RBVs).  LANDSAT 1-3 altitude: 907-915 km inclination: 99.2 degrees orbit: sun-synchronous polar orbit period: 103 minutes revisit time: 18 days  RBV sensors The payloads of the first two satellites included a series of three video cameras that took pictures in the visible and infrared bands. The resolution was 80m for 185 x 185km images. The resolution of the images acquired by Landsat 3 was raised to 40m, but the cameras took images in a single panchromatic spectral band (0.5-0.75µm) only.  MSS sensors These mechanical sensors collected information in four spectral bands and over a 185 x 185km area. Since this instrument was developed after the three RBV cameras, these bands were numbered from 4 to 7. Landsat 3’s multispectral scanner included an additional spectral band in the thermal infrared band. Band Spectral band Resolution 4 0,5 - 0,6 µm 79 m x 82 m 5 0,6 - 0,7 µm 79 m x 82 m 6 0,7 - 0,8 µm 79 m x 82 m 7 0,8 - 1,1 µm 79 m x 82 m 240 m x 240 m 8 10,5 - 12,4 µm (LANDSAT 3 only) The second LANDSAT series The next two satellites (LANDSAT 4 and 5) were equipped with two mutispectral sensors, i.e., a multispectral scanner (MSS) and a Thematic Mapper (TM). altitude: 705 km inclination: 98.2 degrees orbit: sun-synchronous polar orbit period: 98.9 minutes revisit time: 16 days MSS sensors These scanners were identical to those on the first two Landsat satellites. The only difference was that the four spectral bands were numbered from 1 to 4 since the RBVs were no longer used. Landsat 5’s MSS stopped acquiring data in 1992. Band Spectral band Resolution Use 1 0,5 - 0,6 µm 79 m x 82 m Coastal zones, marine sediments 2 0,6 - 0,7 µm 79 m x 82 m Roads and urban areas Plant studies and mapping of 3 0,7 - 0,8 µm 79 m x 82 m earth/water boundaries Plant studies and mapping of 4 0,8 - 1,1 µm 79 m x 82 m earth/water boundaries TM sensors These high-resolution scanners have seven spectral bands and always cover a 185 x 185 km area. Band Spectral band Resolution Use Ground/plants differentiation, 1 0,45 - 0,52 µm 30 m x 30 m coastal zones 2 0,52 - 0,60 µm 30 m x 30 m Vegetation 3 0,63 - 0,69 µm 30 m x 30 m Plant species differentiation 4 0,76 - 0,90 30 m x 30 m Biomass 5 1,55 - 1,75 µm 30 m x 30 m Snow/cloud differentiation 6 10,4 - 12,5 µm 120 x 120 m Thermal 7 2,08 - 2,35 µm 30 m x 30 m Lithology  Channel Wavelength Range Application TM 1 0.45 - 0.52 (blue) soil/vegetation discrimination; coastal mapping; cultural/urban feature identification TM 2 0.52 - 0.60 (green) green vegetation mapping (measures reflectance peak); cultural/urban feature identification TM 3 0.63 - 0.69 (red) vegetated vs. non-vegetated and plant species discrimination (plant chlorophyll absorption); cultural/urban feature identification TM 4 0.76 - 0.90 (near IR) identification of plant/vegetation types, health, and biomass content; soil moisture TM 5 1.55 - 1.75 (short wave IR) sensitive to moisture in soil and vegetation; discriminating snow and cloud-covered areas TM 6 10.4 - 12.5 (thermal IR) vegetation stress and soil moisture discrimination related to thermal radiation; thermal mapping (urban, water) TM 7 2.08 - 2.35 (short wave IR) discrimination of mineral and rock types; sensitive to vegetation moisture content  LANDSAT 7 15 April 1999, at Vandenberg Air Force Launch Date Base in California Spatial Resolution 30 meters 705 +/- 5 km (at the equator) sun- Orbit synchronous Orbit Inclination 98.2 +/- 0.15 Orbit Period 98.9 minutes Grounding Track Repeat Cycle 16 days (233 orbits) Resolution 15 to 90 meters  ETM+ Essentially an advanced version of TM: Same 7 bands Additional Band 8: Panchromatic Resolution: 15m Band Number Spectral Range(microns) Ground Resolution(m) 1.45 to.515 30 2.525 to.605 30 3.63 to.690 30 4.75 to.90 30 5 1.55 to 1.75 30 6 10.40 to 12.5 60 7 2.09 to 2.35 30 Pan.52 to.90 15  LANDSAT 8 LANDSAT 8 satellite has two main sensors: the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS) OLI: 9 spectral bands -visible, near-infrared, and shortwave light -185 kilometer (115 mile) wide swath of the Earth -15-30 meter resolution -providing sufficient resolution to distinguish features like urban centers, farms, forests and other land uses. TIRS was added to the satellite mission when it became clear that state water resource managers rely on the highly accurate measurements of Earth's thermal energy  OLI multispectral bands 1-7,9: 30-meters OLI panchromatic band 8: 15-meters TIRS bands 10-11: collected at 100 meters but resampled to 30 meters to match OLI multispectral bands Approximate scene size is 170 km north-south by 183 km east-west Landsat 8 Wavelength Resolution Bands (micrometers) (meters) Band 1 - Coastal 0.43 - 0.45 30 aerosol Band 2 - Blue 0.45 - 0.51 30 Band 3 - Green 0.53 - 0.59 30 Operational Band 4 - Red 0.64 - 0.67 30 Land Imager Band 5 - Near (OLI) 0.85 - 0.88 30 Infrared (NIR) and Band 6 - SWIR 1 1.57 - 1.65 30 Thermal Band 7 - SWIR 2 2.11 - 2.29 30 Infrared Sensor Band 8 - 0.50 - 0.68 15 (TIRS) Panchromatic Band 9 - Cirrus 1.36 - 1.38 30 Launched Band 10 - Thermal February 11, 2013 Infrared (TIRS) 1 10.60 - 11.19 100 * (30) Band 11 - Thermal 11.50 - 12.51 100 * (30) Infrared (TIRS) 2 Comparison of OLI and TIRS with ETM+  The new cirrus band (Band 9: 1.36-1.39 μm) allows for better detection of cirrus cloud contamination. The old Landsat sensors included bands that made it hard to detect these high- altitude, cold, and wispy clouds. This new cirrus band with center wavelength of 1.375 microns attempts to detect the light, which is reflected by the high-altitude clouds but is absorbed by the water vapour closer to the ground