@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix ns0: <http://gcmd.gsfc.nasa.gov/kms#> .

<https://gcmd.earthdata.nasa.gov/kms/concept/942876b3-fbd5-43d9-9e1f-170682f7b5b3>
  skos:prefLabel "Laser Ranging"@en ;
  a skos:Concept ;
  skos:narrower <https://gcmd.earthdata.nasa.gov/kms/concept/ab5ca508-7ae5-4ede-8c04-5998af821ff7> .

<https://gcmd.earthdata.nasa.gov/kms/concept/ab5ca508-7ae5-4ede-8c04-5998af821ff7>
  ns0:altLabel [ ] ;
  skos:definition """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.

Summary provided by http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1978-064A-06


Group: Instrument_Details
   Entry_ID: LT (SEASAT 1)
   Group: Instrument_Identification
      Instrument_Category: Earth Remote Sensing Instruments
      Instrument_Class: Passive Remote Sensing
      Instrument_Type: Positioning/Navigation
      Instrument_Subtype: Laser Ranging
      Short_Name: LT (SEASAT 1)
      Long_Name: SEASAT 1 Laser Tracking
   End_Group
   Group: Associated_Platforms
      Short_Name: SEASAT 1
   End_Group
   Online_Resource: http://nssdc.gsfc.nasa.gov/nmc/experimentDisplay.do?id=1978-064A-06
   Creation_Date: 2009-07-02
   Group: Instrument_Logistics
      Instrument_Owner: USA/NASA
   End_Group
End_Group"""@en ;
  skos:prefLabel "LT (SEASAT 1)"@en ;
  skos:inScheme <https://gcmd.earthdata.nasa.gov/kms/concepts/concept_scheme/instruments> ;
  skos:broader <https://gcmd.earthdata.nasa.gov/kms/concept/942876b3-fbd5-43d9-9e1f-170682f7b5b3> ;
  a skos:Concept .