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

摘要

The French Transportable Laser Ranging Station (FTLRS) is a highly mobile satellite laser ranging (SLR) system unit that weighs 300 kg and is housed in eight containers. This telemetry laser station is dedicated to the tracking of geodetic satellites equipped with retroreflectors. There are fascinating uses in the geosciences for such a system: in tectonics, oceanography, terrestrial reference frames, and precise positioning. The idea is to use a very small 13-cm-diameter telescope installed on a motorized mount and derived from a geodetic motorized theodolite of high precision. The laser is also compact, and the use of an avalanche photodiode makes detection possible at a single photoelectron level. On-site installation of this new SLR system is fast, and the system's routine operation is quite automated. It started 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 Geodynamic Earth Orientation Satellite (LAGEOS) at 6000 km in a further step. The standard error of individual measurements during the first observation campaign in Corsica is estimated to be of the order of 2-3 cm. Since then, significant improvements have been implemented. A technical description of the FTLRS is given, and the main results of the Corsica campaign are summarized.