Sejarah Satelit Landsat 4

Landsat 4 History

July 16, 1982 – (placed in standby in January 1986) December 14, 1993
Decommissioned: June 15, 2001

Figure 1. Landsat 4

Participants

• NASA
• National Oceanic and Atmospheric Administration (NOAA)
• Earth Observation Satellite Company (EOSAT)
• Department of the Interior (DOI) U.S. Geological Survey (USGS)

Launch

• Date: July 16, 1982
• Vehicle: Delta 3920
• Launched by: NASA
• Site: Vandenberg Air Force Base, California

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
• Three Nickel Cadmium (NiCd) batteries provide 100 Ampere-Hour (AHr ) total
• Retractable boom (4 m long) with 2 powered joints supports the articulated High Gain Antenna, which downlinked data via the Tracking and Data Relay Satellite System (TDRSS)
• Weight: approximately 4,300 lbs (1,942 kg)

Communications

• Direct downlink with TDRSS
• Data rate: 85 Mbps
• Communications system uses S, X, L, and Ku Bands
• Quantization: 8 bit (256 levels)

Orbit

• Worldwide References System-2 (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 Landsat 1 and 2):
• Band 4 Visible (0.5 to 0.6 µm)
• Band 5 Visible (0.6 to 0.7 µm)
• Band 6 Near-Infrared (0.7 to 0.8 µm)
• Band 7 Near-Infrared (0.8 to 1.1 µm)
• Data: 100 kHz 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 (TM)

• Added the mid-range infrared to the data
• Seven spectral bands, including a thermal band:
• Band 1 Visible (0.45 – 0.52 µm) 30 m
• Band 2 Visible (0.52 – 0.60 µm) 30 m
• Band 3 Visible (0.63 – 0.69 µm) 30 m
• Band 4 Near-Infrared (0.76 – 0.90 µm) 30 m
• Band 5 Near-Infrared (1.55 – 1.75 µm) 30 m
• Band 6 Thermal (10.40 – 12.50 µm) 120 m
• Band 7 Mid-Infrared (IR) (2.08 – 2.35 µm) 30 m
• Ground Sampling Interval (pixel size): 30 m reflective, 120 m thermal

Other Characteristics

• Scene size: 170 km x 185 km (106 mi x 115 mi)
• Also known as Landsat-D
• Design Life: Minimum of 3 years

Sumber :
http://landsat.usgs.gov/about_landsat4.php