Sejarah Satelit Landsat 7

Landsat 7 History

April 15, 1999 - present

Figure 1. Landsat 7




Movie 1. Launch of Landsat 7
Download Small Landsat 7 Launch Movie .mov (23.2 MB)
Download Large Landsat 7 Launch Movie .mov (121 MB)
Download QuickTime Player


Participants

• NASA
• National Oceanic and Atmospheric Administration (NOAA) (initial participant)
• Department of the Interior (DOI) U.S. Geological Survey (USGS)
• Spacecraft bus: Lockheed Martin Missiles & Space
• Enhanced Thematic Mapper Plus (ETM+): Hughes Santa Barbara Remote Sensing

Launch

• Date: April 15, 1999
• Vehicle: Delta II
• Launched by: NASA
• Site: Western Test Range at Vandenberg Air Force Base, California

Figure 2. Landsat 7

Spacecraft

• Power provided by a single Sun-tracking solar array and two 50 Ampere-Hour (AHr), Nickel Cadmium (NiCd) batteries
• Attitude control provided through four reaction wheels (pitch, yaw, roll, and skew); three 2-channel gyros with celestial drift updating; a static Earth sensor; a 1750 processor; and torque rods and magnetometers for momentum uploading
• Orbit control and backup momentum unloading provided through a blow-down monopropellant hydrazine system with a single tank containing 270 pounds of hydrazine, associated plumbing, and twelve 1-pound-thrust jets
• Weight: approx. 4,800 lbs (2,200 kg)
• Length: 4.3 m (14 ft)
• Diameter: 2.8 m (9 ft)

Communications

• Direct Downlink with Solid State Recorders (SSR)
• Data rate: 150 Mbps

Orbit

• Worldwide Reference System-2 (WRS-2) path/row system
• Sun-synchronous orbit at an altitude of 705 km (438 mi)
• 233 orbit cycle; covers the entire globe every 16 days (except for the highest polar latitudes)
• Inclined 98.2° (slightly retrograde)
• Circles the Earth every 98.9 minutes
• Equatorial crossing time: 10:00 a.m. +/- 15 minutes

Sensors
Enhanced Thematic Mapper Plus (ETM+)

• Eight spectral bands, including a pan and 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 (0.77 – 0.90 µm) 30 m
• Band 5 Near-Infrared (1.55 – 1.75 µm) 30 m
• Band 6 Thermal (10.40 – 12.50 µm) 60 m Low Gain / High Gain
• Band 7 Mid-Infrared (2.08 – 2.35 µm) 30 m
• Band 8 Panchromatic (PAN) (0.52 - 0.90 µm) 15 m
• Ground Sampling Interval (pixel size): 30 m reflective, 60 m thermal
• Added the Band 6 Low and High gain 60 m thermal bands
• On-board calibration was added to Landsat 7: a Full Aperture Solar Calibrator (FASC) and a Partial Aperture Solar Calibrator (PASC), in addition to the 2 calibration lamps

Other Characteristics

• Scene size: 170 km x 185 km (106 mi x 115 mi)
• Design Life: Minimum of 5 years

Figure 3. Landsat 7

sumber :
http://landsat.usgs.gov/about_landsat7.php