Satellite Parameters for POD
The Sentinel-3 mission is supported by two identical spacecraft, Sentinel-3A and Sentinel-3B, flying in the same orbital plane with a phase shift of ±140º. An overall description of the satellite is available, explaining the main instruments and the geometry of the satellites. Additionally, they are equipped with a full Precise Orbit Determination (POD) package consisting of two GPS receivers, one DORIS receiver and one Laser Retro Reflector (LRR) instrument for Satellite Laser Ranging (download a document describing the Sentinel-3 mission in more detail).
Drawing of Sentinel-3A satellite showing the GPS, DORIS and LRR receivers (image credit: ESA)
For Precise Orbit Determination processing it is of paramount importance to know in great detail the mass history of the satellite, the evolution of its centre of gravity, the manoeuvre history and the attitude information. Moreover, for GNSS based processing, the location and orientation of the antennae are required. In the case of the manoeuvre and mass history file (including the CG position), available hereafter, a historical record is kept since the launch of the satellite:
For Sentinel-3 mission, the attitude information is provided as an official POD product (see POD Products and Requirements section). In all timeliness categories, ranging from Near-Real Time (NRT) to Non-Time Critical (NTC), platform data files containing the platform off nadir angles are computed. The user community can find the precise platform data files (NTC) as well as the Quaternions files on the ESA Copernicus Open Access Hub.
For the convenience of users, another file combining information on manoeuvres and GNSS outages for the mission is provided below:
Please note that all of the files provided above contain a header that explains the format of their content.
The GPS Antenna absolute phase centre offset and variations (PCO/PCV) of both GPS receivers is located in this ANTEX file.