The routine accuracy assessment of Sentinel-1 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.
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 2: Orbit comparison of Sentinel-1 NRT orbital products (AUX_RESORB) against ESOC precise solution
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 the NTC product: