New Capabilities of High Precision Geodesy with Galileo
Perosanz, F ²; Loyer, S ¹; Valette, J J ¹; Rhekis, S ^2
1Collecte Localisation Satellites; ²CNES/GRGS Centre National d’Etudes Spatiales

The Galileo phase signals accuracy will be similar to the GPS or GLONASS ones. The new frequencies and the new satellite constellation will then contribute without any doubt to the high precision positioning. High precision geodesy here concerns non real time applications and covers the range from a few mm up to 1 m accuracy level. More precisely our scope is focussed on PPP or Precise Point Positioning. Classically, the PPP consists in calculating a receiver antenna position using only its own GNSS observations (Rinex file) and external information such as precise satellite ephemeris, clocks, antenna corrections… The method is very attractive and low cost compared to differential GPS techniques that require processing of baselines with neighbouring stations of a fiducial network. CNES/GRGS with support of CLS intends to become an IGS analysis center in 2007. The two teams are also involved in Galileo orbit investigation and will be able to provide in a regular basis those data needed for PPP. What will be a real new PPP capability with Galileo is the possibility to download data via the Commercial Services and consequently to make possible PPP at the receiver level. The applications will be presented. They may be industrial applications such as offshore survey or construction in regions where infrastructures are lacking but may also be scientific applications for ground deformation monitoring, altimetry reference… The Galileo, GPS and GLONASS constellations will provide complementarity and redundancy in terms of number of observations, geometry and signals at different frequencies. The benefit for positioning will be discussed. Finally, the user needs for positioning solution integrity and PPP service guarantee will also be analyzed.