28.07.2020 08:17 Age: 329 days

[SARAL/AltiKa] GDR-F reprocessing on-going

Category: Operational news

We are pleased to inform you that the SARAL/AltiKa GDR-F reprocessing is on-going and already partly available.

The SARAL/Altika GDR-F standard has been developed since 2016, following OSTST recommendations. It includes many improvements compared with the previous GDR-T Standard among which :

-Updated geophysical corrections: 

    .FES2014b & GOT4.10 ocean tide models

    .CNES/CLS 2015 and DTU 2015 Mean Sea Surface 

   . CNES/CLS 2018 Mean Dynamic Topography model

   . S. Desai pole tide with new IERS linear mean pole

    .EGM 2018 geoid model 

    .New Wet & dry tropospheric model correction based on 3D ECMWF fields

    .New Atmospheric Attenuation model correction based on 3D ECMWF fields

    .Parameter SSB (SWH, wind and swell) 

-New geophysical corrections:

    .E.Zaron internal tide model

-New Radiometer processing algorithms

-Updated altimeter calibration schemes

-NetCDF-4/HDF5 classic model format with native compression


The exhaustive list of evolution can be found here

The assessment of the SARAL/Altika GDR-F Standard can be found here 

 While GDR-F standard has already been the operational baseline standard for SARAL/Altika GDR since January 2020, the historical data are currently being reprocessed to reach this standard, as announced during the latest OSTST meeting.

 Indeed, year 2013 and 2014 are already fully reprocessed and validated. These data are already available on AVISO+ ftp.

Your feedback would be appreciated !


Note that the zipped container for data delivery is no longer necessary thanks to the native compression. Operational delivery will no longer be available in zip format from cycle 140 onwards, with retroactive effect on previous cycles.


The complete reprocessing covering remaining years, 2015 to early 2020, will be delivered within the following weeks.

 For any question, please contact the AVISO heldesk :