The latest version of the Envisat DORIS Precise Orbit product (DOR_VOR_AX) was generated by the Centre de Traitement Doris Poseidon (CTDP) using the Geophysical Data Records F standards (GDR-F). The product is used to obtain the satellite orbital parameters (latitude, longitude, height and height rate) by using orbit computation routines.
The most significant changes related to the GDR-F standards concern the new ocean tide model (FES2014) and the updated Terrestrial Reference Frame (ITRF2014). The new standards significantly improve all Precise Orbit Determination (POD) metrics with respect to GDR-E: the mean difference and variance of Sea Surface Height (SSH) at crossovers is slightly reduced.
The DOR_VOR_AX product adopts the Envisat format, and the size is 0.2 Mbytes per orbit.
Users are recommended to apply the GDR-F version, but the previous datasets are still available (i.e. GDR-D and GDR-E versions).
See further details in the readme file for Envisat DORIS Precise Orbit Determination files.
Comparison of Envisat Sea Level Anomaly trends obtained using DORIS Precise Orbit GDR-E and F standards. North/South patterns are evident. Credits: CNES/CLS.