Satellite Parameters for POD
The Sentinel-1 mission is supported by two identical spacecraft, Sentinel-1A and Sentinel-1B, flying in the same orbital plane with a phase shift of 180º. An overall description of the satellite is available, showing the main instruments and the geometry of the satellites. Additionally, they are equipped with two dual frequency RUAG GPS receivers to allow POD in order to meet the astringent accuracy requirements of the mission.
Drawing of Sentinel-1A showing the GPS 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 CoG position), available hereafter, a historical record is kept since the launch of the satellite:
For Sentinel-1 mission, the attitude information is meant to be provided as an official POD product (see POD Products and Requirements). However, for the time being, this file is not being generated. The official POD Restituted attitude files shall be made available as soon as these products are generated.
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.