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Landsat 4 History
July 16, 1982 – January 1986 (standby) December 14, 1993
Decommissioned: June 15, 2001
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Figure 1. Landsat 4
Participants
- National Aeronautics and Space Administration (NASA)
- National Oceanic and Atmospheric Administration (NOAA)
- Earth Observation Satellite Company (EOSAT)
- Department of Interior (DOI) (U.S. Geological Survey (USGS))
Launch
- Date: July 16, 1982
- Vehicle: Delta 3920
- Launched by: NASA
- Site: Vandenberg Air Force Base, CA
Spacecraft
- 3-axis stabilized, zero momentum with control of 0.01 deg using reaction wheels
- Aluminum with graphite struts
- Hydrazine propulsion system
- Single solar array with 1-axis articulation produces 1430 W (BOL)
- Three NiCd batteries provide 100 AHr total
- Retractable boom (4m long) with 2 powered joints supports the articulated HGA which downlinks data via Tracking and Data Relay Satellite System (TDRSS)
- Weight: approximately 1942 kg
Communications
- Direct downlink withTDRSS
- Data rate: 85 Mbps
- Communications system uses S,X,L, and Ku-Bands
- Quantisation: 8 bit (256 levels)
Orbit
- WRS-2 path/row system
- Circular, sun-synchronous, near-polar orbit at an altitude of 705 km (438 mi)
- Inclined at 98.2°
- Circled the Earth every 99 minutes
- Repeat cycle: 16 days
- Equatorial crossing time: 9:45 a.m. +/- 15 minutes
- Swath width: 185 km (115 mi)
Sensors
Multispectral Scanner (MSS)
- Four spectral bands (identical to L1 and L2)
- Band 4 Visible (0.5 to 0.6 µm)
- Band 5 Visible (0.6 to 0.7 µm)
- Band 6 Near Infrared (NIR) (0.7 to 0.8 µm)
- Band 7 NIR (0.8 to 1.1 µm)
- Data: 100kHz digital
- Six detectors for each reflective band provided six scan lines on each active scan
- Ground Sampling Interval (pixel size): 57 x 79 m
Thematic Mapper
- Added the mid-range infrared to the data
- Seven spectral bands, including a thermal band:
- Band 1 Visible (0.45 – 0.52µm) 30m
- Band 2 Visible (0.52 – 0.60µm) 30m
- Band 3 Visible (0.63 – 0.69µm) 30m
- Band 4 NIR (0.76 – 0.90µm) 30m
- Band 5 NIR (1.55 – 1.75µm) 30m
- Band 6 Thermal (10.40 – 12.50µm) 120m
- Band 7 Mid IR (2.08 – 2.35µm) 30m
- Ground Sampling Interval (pixel size): 30m reflective 120m thermal
Other Characteristics
- Scene Size: 184 x 185.2 km
- Also known as Landsat - D
- Design Life: Minimum of 3 years
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U.S. Department of the Interior |
U.S. Geological Survey
