GIOVE-A Precise Orbit Determination based on SLR and Radio Tracking Data
Melachroinos, S. A.¹; Perosanz, F.²; Flavien, M.³; Biancale, R.^2
1GRGS; ²GRGS/CNES; ³CNES

The first European Galileo In-Orbit Validation Element (GIOVE-A) satellite has been launched the 28th of December 2005. The radio tracking of this satellite from a dedicated global network of 13 hybrid GPS/Galileo Septentrio receivers allows the computation of GIOVE-A satellite orbit. In addition, this satellite like any future Galileo spacecraft is equipped with laser retro-reflectors. The SLR global tracking network is being tracking the GIOVE-A satellite since May 2006.The combination of GPS and Galileo signals makes possible the observations of common parameters like receiver clocks. However inter-systems biases must be carefully considered.

This presentation shows a preliminary evaluation of the GIOVE-A satellite precise orbit determination computed by the CNES/GRGS group with the GINS GNSS software. The SLR and radio solutions are compared and a decimetre level of precision is demonstrated. A GIOVE-A dedicated solar radiation pressure model is also presented