French transportable laser ranging station: scientific objectives, technical features, and performance

The French Transportable Laser Ranging Station (FTLRS) is a highly mobile s atellite laser ranging (SLR) system unit that weighs 300 kg and is housed i n eight containers. This telemetry laser station is dedicated to the hackin g of geodetic satellites equipped with retroreflectors. There are fascinati ng uses in the geosciences for such a system: in tectonics, oceanography, t errestrial reference frames, and precise positioning. The idea is to use a very small 13-cm-diameter telescope installed on a motorized mount and deri ved from a geodetic motorized theodolite of high precision. The laser is al so compact, and the use of an avalanche photodiode makes detection possible at a single photoelectron level. On-site installation of this new SLR, sys tem is fast, and the system's routine operation is quite automated. It star ted its operational phase in late 1996. At present, it can track satellites at altitudes of as much as 3000 km and is designed to range to the Laser G eodynamic Earth Orientation Satellite (LAGEOS) at, 6000 km in a further ste p. The standard error of individual measurements during the first observati on campaign in Corsica is estimated to be of the order of 23 cm. Since then , significant improvements have been implemented. A technical description o f the FTLRS is given, and the main results of the Corsica campaign are summ arized. (C) 2000 Optical Society of America OCIS codes: 120.0120, 120.3930, 120.3940, 120.4820, 140.0140.