Minimize Orbit Comparisons

The routine accuracy assessment of Sentinel-2 is carried out by comparing the generated orbital products by the Copernicus POD Service against external orbits provided by ESOC, generated from independent observation RINEX [ftp://igscb.jpl.nasa.gov/pub/station/general/antex14.txt] directly decoded from the GPS L0 files.

In the case of the predicted orbit, given its more relaxed requirements, its accuracy assessment is carried out against the RESORB product after verifying that this one is close to the external solution.

The following figures show that the accuracy requirements are regularly met. The cases in which they are not are usually related to manoeuvres or GPS data outages.


Figure 1: Orbit comparison of Sentinel-2 NRT orbital products (AUX_RESORB) against ESOC precise solution

Figure 2: Orbit comparison of Sentinel-2 PRE orbital products (AUX_PREORB) against CPOD RESORB


Further comparisons against the rest of the external validation centres which belong to the POD Quality Working Group are carried out every four months for the Regular Service Review. As a summary of the latest one, the following comparisons are available for a CPOD precise orbit generated ad-hoc with NTC timeliness (although there is at the moment no such official POD product for Sentinel-2):


Figure 3: Orbit comparison of Sentinel-2A NTC orbital products (AUX_POEORB) against all external validation centres for the latest Regular Service Review (Feb-May '16)