| Instrument: LRR : Laser Retro-Reflector |
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Associated Platforms TSX GOCE ERS-2 ERS-1 ENVISAT CRYOSAT-2 Related Data Sets View all records related to this instrument Description The European Remote Sensing Satellites (ERS-1 and ERS-2) are equipped with a Laser Retroreflector (LRR), a passive optical instrument operating in the infra-red, to permit ranging of the satellite by the use of Laser Tracking Stations, and therefore the accurate determination of its height. These measurements allow: - calibration of the Radar Altimeter altitude measurements with an error of 10 cm - improvement of the satellite orbit determination ensuring the production of a global ephemeris accurate to better than 1-2 m for the radial component. The operating principle is to measure the time of a round trip of laser pulses reflected from an array of corner cubes mounted on the Earth-facing side of the spacecraft's Payload Electronics Module. This array consists of a hemispherical housing with an arrangement of one nadir-looking corner cube in the centre, surrounded by an angled ring of eight corner cubes. Each corner cube is individually made to compensate for satellite motion in reflecting incident laser energy back exactly along its incoming path. This allows laser ranging for satellite passes in the range of 0-360 degrees azimuth and 30 to 90 degrees elevation at the ground. Instrument characteristics: ------------- Wavelength: 350-800 nm optimised for 532 nm Efficiency: less or equal than 0.15 end-of-life Reflection Coefficient: less or equal than 0.80 end-of-life Field of view: elev. half-cone angle 60 degrees; azimuth 360 degrees Diameter: more or equal than 20 cm -------------- For any query, please refer to: ESA/ESRIN Earth Observation Help Desk http://earth.esa.int E-mail: eohelp@esa.int Phone: +39 06 94180777 Fax: +39 06 94180292 Address: ESA/ESRIN Via G.Galilei 00044 Frascati Italy Online Resources http://envisat.esa.int/instruments/lrr/ Instrument Logistics Instrument Owner: ESA |
