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Laser Tracking

NSSDCA ID: 1978-064A-06

Mission Name: Seasat 1
Principal Investigator:Mr. James G. Marsh


This system was one of the devices to support precision orbit determination for Seasat 1. Laser corner reflectors, composed of 96 fused silica 3.75-cm hexagonal corner cube retroreflectors, and ground-based laser systems were used to obtain precise satellite tracking information. The retroreflector array was configured as a single ring of cube corners 1.27 m in diameter. Sixteen of the cube corners were tilted away from the axis of the ring by an angle of 25 deg and the remaining 80 cubes by an angle of 50 deg. Because of the great distance of the array from the center of mass of the satellite the range correction varied from -5.28 m at zenith to -3.08 m near the horizon. When illuminated by laser light pulses from the ground, each retroreflector cube in the array reflected the light pulses back to a telescope/receiver on the ground. A digital counter recorded the time of flight of the laser light pulses from the ground to the satellite and back to the ground. Range was determined from this time. NASA, USAF, SAO (Smithsonian Astrophysical Observatory) and foreign laser tracking stations tracked this satellite.

Alternate Names

  • Seasat1/LaserTracking


  • Earth Science: Geophysics/Geodesy

Additional Information

Questions and comments about this experiment can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. James G. MarshPrincipal InvestigatorNASA Goddard Space Flight Center
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