The following message has been forwarded to all registered PO.DAAC users on
behalf of the Jason-1 Project:
We are pleased to announce that reprocessing of Jason-1 data is currently in
progress.
The data are available as version "E" GDR data products at the
AVISO and PODAAC ftp sites as follows:
ftp://avisoftp.cnes.fr/AVISO/pub/jason-1/
ftp://podaac.jpl.nasa.gov/allData/jason1/L2/
All products are available in NetCDF format, and are available in three
forms, similar to those from the Jason-2/OSTM mission:
-
The native (N) dataset containing 1-Hz records as well as 20-Hz high-rate
values (GDR)
-
The reduced (R) 1-Hz subset of the full GDR data set. (GDR-SSHA)
-
The expert sensor (S) data set containing the full radar-echo waveforms
(S-GDR) in addition to the GDR dataset. (Please note that SGDRs will be
available with latency of 4-8 weeks after GDR release.)
A User Handbook is provided at the above-mentioned ftp areas.
ftp://avisoftp.cnes.fr/AVISO/pub/jason-1/documentation_gdr_e/Handbook_Jason-1_v5.0_Sept2015.pdf
ftp://podaac.jpl.nasa.gov/allData/jason1/L2/docs/Handbook_Jason-1_v5.0_Sept2015.pdf
The User Handbook provides details on the evolution of the version
"E" products compared to the preceding version "C"
products.
The primary evolutions include:
-
Products are provided in NetCDF format instead of binary.
-
Orbit solutions are from so-called version "E" standards, based
on ITRF08.
-
Time tags are adjusted to correct for the datation bias that existed in
previous versions (A, B, C) of the Jason-1 products.
-
Altimeter range instrument correction and associated Ku- and C-band range
account for error in internal path delay. (+63.9 mm compared to version
C)
-
Recalibrated radiometer data, and application of near-land path delay
algorithm.
-
Altimeter wind speeds are recomputed using recalibrated atmospheric
attenuations from radiometer.
-
New Ku- and C-band sea state bias models, and values that are computed
using revised wind speeds.
-
The ionosphere correction is recomputed using updated altimeter ranges and
sea state bias correction
-
Current state-of-the art geophysical models including:
-
Model dry troposphere correction from ECMWF Reanalysis (ERA) in addition
to previously available operational ECMWF
-
Model wet troposphere corrections from ECMWF Renalysis (ERA) in addition
to previously available operational ECMWF
-
Model wind speeds from ECMWF Reanalysis (ERA) in addition to previously
available operational ECMWF.
-
Inverse barometer and high-frequency corrections using ECMWF Reanalysis
(ERA) in addition to previousl available operational ECMWF.
-
Ocean tides from FES2014 and GOT4.10 models
-
Mean sea surface from MSS_CNES-CLS11, computed from a 20-year reference
period.
-
Mean dynamic topography from MDT_CNES-CLS13
-
Geoid from EIGEN2008
-
Bathymetry from DTM2000.1
-
Rain flag updated
With this announcement, Jason-1 version E GDRs for 2002-2004 (cycles 1-110)
are now available.
The remaining years are scheduled for release as follows:
-
2005-2008 by the end of October.
-
2009-2013 by the end of November.
Best regards,
The CNES and JPL science data system teams.