Jason 3 GPS derived orbits with ambiguity fixing

Flavien Mercier (cnes, France)


Hanane Ait lakbir (CS-SI, France); Alexandre Couhert (CNES, France)

Event: 2017 Ocean Surface Topography Science Team Meeting

Session: Precision Orbit Determination

Presentation type: Type Oral

The blackjack GPS receiver from Jason 3 measures the same observables as the ground geodetic receivers used at IGS for the GPS constellation orbits and clocks. So it is possible to perform ambiguity fixing in the Jason 3 GPS solutions as for ground stations.
CNES has developed since 2008 a method for fixing ambiguities using ‘phase clocks’. This is currently implemented in the CNES/CLS contribution to IGS (solution grg). The advantage of this approach is that using the grg orbits/clocks products available at IGS, it is possible to fix the ambiguities of the LEO satellite phase measurements, without processing simultaneously the ground stations, as for double difference approaches.
Thanks to the quality of the Jason 3 current GPS orbits (computed with floating ambiguities), it is possible to directly observe and fix the phase ambiguities using orbit determination residuals. Some specificities of the receiver measurements are detailed (pseudo-range biases, receiver widelane bias).
An orbit determination can be performed using directly this new ambiguity solution, with the same measurements, models and parameters as in the current products. This method has been implemented for Jason 3, and the orbits are compared to the current precise orbits.

Oral presentation show times:

RoomStart DateEnd Date
Symphony II Tue, Oct 24 2017,09:45 Tue, Oct 24 2017,10:00
Flavien Mercier