FRENCH TRANSPORTABLE LASER RANGING STATION: POSITIONING CAMPAIGNS FOR SATELLITE ALTIMETER CALIBRATION MISSIONS IN OCCIDENTAL MEDITERRANEAN SEA

Abstract

The paper deals with the presentation of the French Transportable Laser Ranging Station (FTLRS) and its experiences of geographic positioning at Corsica (France). The geodetic site of Ajaccio in Corsica is the main calibration site, in the Mediterranean area, of radars on board altimetric satellite. It has been developed for altimetric and oceanographic missions such as TOPEX/Poseidon (T/P, 1992), Jason-1 (2001), Envisat (2002) and Jason-2 (2008). The FTLRS was deployed there during laser campaigns, on 2002 and 2005, and recently on 2008. Here, we present the analysis results of the SLR data acquired by the FTLRS during 2002 and 2005 campaigns mainly on the low Earth geodetic satellites: Starlette and Stella (altitude of 800 km). The paper describes the different steps of the laser data processing. The average arcs RMS obtained are about 1-2 cm for Lageos-1&-2, Starlette and Stella satellites; it is showed that best results of satellite orbits determination and geocentric positioning are obtained with Eigen-Grace03s gravity model. The difference of FTLRS absolute 3D positioning, between 2002 and 2005, of about 7.7 mm (i.e., 2.6 mm/yr) is less than residual errors of ITRF2005 velocities (of about 4.3 mm/yr). Finally, some suggestions of the use of FTLRS in Algeria for geodetic applications are proposed.