Landsat 3

Landsat 3 Satellite Orbit Facts

• Orbited the Earth at 917 km (570 mi) in a sun-synchronous, near-polar orbit (99.2 degrees inclination)
• Circled the Earth every 103.34 minutes, completing 14 orbits per day
• Had an 18-day cycle and equatorial crossing time of 9:30 a.m. mean local time (+/- 15 minutes). 
• Acquired data on the WRS-1 path/row system, with swath overlap (or sidelap) varying from 14 percent at the Equator to a maximum of approximately 85 percent at 81 degrees north or south latitude. 
• With both Landsat 2 and Landsat 3 orbiting, the US could receive nine-day repeat coverage.

Landsat 3 Instruments

Landsat 3 carried the modified versions of the sensors placed on Landsat 1 and Landsat 2: the Return Beam Vidicon (RBV) and the Multispectral Scanner System (MSS).

Media

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Return Beam Vidicon (RBV)

The RBV sensor utilized vidicon tube instruments containing an electron gun that read images from a photoconductive faceplate similar to television cameras. The data stream received from the satellite was analog-to-digital preprocessed to correct for radiometric and geometric errors. 

The RBV system was redesigned for Landsat 3 to use two cameras, mounted side-by-side, with panchromatic spectral response and higher spatial resolution than on Landsat 1 and Landsat 2, to complement the multispectral coverage provided by the MSS. Each of the cameras produced a swath of about 90 km (for a total swath of 180 km).

• 40-meter-ground resolution
• Two cameras operating in one broad spectral band (green to near-infrared; 0.505–0.750 µm) 
• Data recorded to 70 millimeter (mm) black and white film rolls
• Data: 3.5 MHz FM video

RBV data was rarely used and considered useful for engineering evaluation purposes rather than science analysis. Visit RBV Film Only for more information. 

Multispectral Scanner (MSS)

The MSS sensor was a line-scanning device observing the Earth perpendicular to the orbital track. The cross-track scanning was accomplished by an oscillating mirror; six lines were scanned simultaneously in each of the four spectral bands for each mirror sweep. The forward motion of the satellite provided the along-track scan line progression. The MSS sensor on Landsat 3 originally had five spectral bands, but one failed shortly after launch. 

In early 1980, the MSS experienced an anomaly where the sensor had trouble properly synchronizing scan lines at the beginning of each new line, resulting in data gaps or inconsistencies at the start of each image. This affects about 1/3 of each Landsat 3 MSS image. Visit this page to learn more about the affects of this anomaly. 

• 80-meter ground resolution in four spectral bands:
  • Band 4 Visible green (0.5 to 0.6 µm)
  • Band 5 Visible red (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)
• Six detectors for each spectral band provided six scan lines on each active scan
• Ground Sampling Interval (pixel size): 57 x 79 m
• Scene size: 170 km x 185 km (106 mi x 115 mi)

Visit Landsat 1-5 MSS for more information. 

*In 2011, the Memory of the World Programme, administered through the United Nations Educational, Scientific and Cultural Organization (UNESCO), selected the Landsat Multispectral Scanner (MSS) datasets to be included because they are unique, irreplaceable record of the Earth’s land surfaces, shallow coastal regions, and reefs.  

Landsat 3 Spacecraft Facts

• Manufactured by General Electric (GE) Astrospace
• Weight: approximately 953 kg (2,100 lbs)
• Overall height: 3 m (10 ft)
• Diameter: 1.5 m (5 ft)
• Solar array paddles extend out to a total of 4 m (13 ft)
• 3-axis stabilized using 4 wheels to +/-0.7° attitude control
• Twin solar array paddles (single-axis articulation)
• S-Band and Very High Frequency (VHF) communications
• Hydrazine propulsion system with 3 thrusters