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Laser Retro-Reflector FM
The Laser Retro-Reflector (LRR) is mounted on the nadir face of the Envisat satellite, close to the RA-2 antenna, to support satellite ranging and RA-2 altitude measurement calibration. The LRR is a passive device which will be used as a reflector by ground-based laser-ranging stations using high power pulsed lasers.
The operating principle is to measure, on ground, the time of a round trip of laser pulses reflected from an array of corner cubes mounted on the Earth-facing side of the satellite. The corner cubes are designed to reflect the incident laser beam back directly, making the reflected beam parallel to the incident beam within a few arcseconds.
The corner cubes are made of the highest quality fused silica, optimised for maximum reflectivity, at 532 nm and 694 nm. They are symmetrically mounted on a hemispherical housing with one nadir-looking corner cube in the centre, surrounded by an angled ring of eight corner cubes. This will allow laser ranging in the field of view angles of 360° in azimuth and 60° elevation around the nadir.
The LRR was developed under the leadership of Alcatel Space Industries (F).
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Related linksEnvisat - LRR