News
[Jason-3] GDR-F Announcement
We are pleased to inform you that the Jason-3 GDR standard will upgrade to GDR-F on 2020 October, 29th
GDR-F will become the operational baseline standard for Jason-3 OGDR and IGDR (from cycle 174 onwards) and GDR (from cycle 171 onwards)
The Jason-3 GDR-F standard, following OSTST recommendations, includes many improvements compared with the previous GDR-D Standard among which :
- Updated orbit model POE-F
- Updated geophysical corrections:
- FES2014 & GOT4.10 ocean tide models
- CNES/CLS 2015 and DTU 2018 Mean Sea Surface
- CNES/CLS 2018 Mean Dynamic Topography model
- New Wet & dry tropospheric model correction based on 3D ECMWF fields
- New Atmospheric Attenuation model correction based on 3D ECMWF fields
- S. Desai pole tide with 2017 IERS linear mean pole
- 3-Parameter SSB (SWH, wind and swell)
- Smoothed ionospheric bifrequency correction
- Data referenced wrt WGS84
- New geophysical corrections:
- E. Zaron internal tide model
- Sandwell & Smith Global Slope Correction
- A new ssha formula : substraction of Internal Tides & Non-equilibrium Ocean Tides
- A new AMR calibration that references the absolute calibration that we expect to receive from Sentinel-6
- A new retracking at GDR level : Adaptive retracking
- A new waveform classification based on neural network
- New additional fields :
- Coastal distance
- OISST
- OSISAF ice concentration
- MFWAM swell period & direction
- Jason-CS/Sentinel6 rain flag approach
- A new way to take into account the instrumental filter calibration (CAL2)
- A large renaming of NetCDF variables, use of NetCDF groups (reconciliation with S6/JCS format)
- NetCDF-4/HDF5 classic model format with native compression
The user documentation (User Product Description and Handbook) are available on AVISO+ website :
Samples of GDR-F files are available on AVISO+ ftp
This modification concerns the Native products as well as the Sensor products (SGDRs) and the Reduced products (GDR-SSHA)
Note that the GDR-F standard has no backward compatibility with GDR-D, due to variables renaming and the use of NetCDF groups.
After the standard switch, a double standard production “GDR-D” and “GDR-F” will be mainted during three months at IGDR and GDR levels.
The whole lifetime of Jason-3 data will be reprocessed with GDR-F standard, delivery is scheduled April 2021.
The Jason-2 reprocessing at GDR-F standard is scheduled end 2021.
Please, feel free to contact us for any question (aviso@altimetry.fr).
François Bignalet-Cazalet, on behalf of the Jason-3 GDR-F Team
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