Difference of LAGEOS satellite response from raw data analysis of the collocation experiment between the Grasse Satellite and Lunar Laser Ranging stations
Résumé
We performed a collocation experiment at the Grasse observatory (France) between three independent laser ranging instruments: the Satellite Laser Ranging (SLR), the Lunar Laser Ranging (LLR) station, and the French Transportable Laser Ranging Station (FTLRS). The normal point analysis of the common passes on LAGEOS-1 and-2 satellites showed a systematic difference of 13 mm between the SLR and the LLR station results. 9 mm are already explained with instrumental reasons for the LLR station (photodiode center-edge effect and velocity aberration). To explain the residual bias, from raw data and geometrical analysis, we computed the difference of the LAGEOS satellite ranges due to instrumental differences. We show that the satellite signature effectively depends on the station at the level of 3 mm. Thus, we are able to explain at the 1 mm level the bias difference of 12 mm between the 2 considered stations. We also propose to adopt a LAGEOS center of mass correction value depending on the laser ranging station technical features, dependency especially coming from the difference between single and multi photoelectron detection levels. We found that this difference can reach a few millimeters with resect to the standard value used for the laser ranging data analysis.
Domaines
Planète et Univers [physics]
Origine : Fichiers produits par l'(les) auteur(s)