Category: Operational news

Last week the Jason-2 OGDR near real-time processing software (TM-NRT) was upgraded to version 3.0 at both NOAA and EUMETSAT. This is a major system upgrade from the previous version (2.3), but has minimal impact on users. There are no format changes to the products.

TM-NRT-V3 contains a new internal ftp module, provides a common processing package for both Jason-2 and SARAL/Altika, and corrects a few minor anomalies within the OGDR products. The correction of these anomalies is the only difference in data content that end users will observe:
- Several one-byte flags were incorrectly defaulted to 0 vs. 127. They now have a proper _FillValue of 127.
- Four generic processing algorithms didn't properly handle defaults values. These have all been corrected
- The flag 'alt_state_flag_tracking_mode_20hz' was set to 0, indicating split-gate tracking, when it should have been 1, indicating median tracking mode. The flag is now correctly set to 1 during median tracking.
- The construction of 'net_instr_corr_swh_ku' was incorrect due to a calculation with a wrong bit number. This has been corrected.
- A few netCDF variable attributes (NOT variable names) were misspelled or contained typographical errors that have been corrected:

variable	variable_attribute	change from V2.3 to V3.0
lon	comment	Greenwich spelling corrected
lon_20hz	comment	Greenwich spelling corrected
orb_state_flag_rest	comment	meaning of flag state '8' corrected
model_dry_tropo_corr	standard_name	troposphere spelling corrected
model_wet_tropo_corr	standard_name	troposphere spelling corrected
rad_wet_tropo_corr	standard_name	troposphere spelling corrected
rad_wet_tropo_corr	quality_flag	"and" added before "interp_flag_tb"

None of these changes should necessitate changes to your processing code. Due to unexpected earth terminal testing at the NOAA/Wallops ground station, a single (short) OGDR was produced with TM-NRT-V3.0 prior to the planned transition on the morning of 14-Jan-2010. This single OGDR is JA2_OPN_2PcS056_139_20100113_200656_20100113_202210. All OGDRs produced by both NOAA and EUMETSAT after the planned transition are now based on TM-NRT-V3.0. This can be confirmed via the 'references' global netCDF attribute: "L1 library=V3.1p1, L2 library=V3.0p1, Processing Pilot=V3-0p1p2p3". The last OGDR produced with TM-NRT-V2.3 is:
JA2_OPN_2PcS056_146_20100114_015512_20100114_035302 The first (full) OGDR produced with TM-NRT-V3.0 is:
JA2_OPN_2PcS056_148_20100114_035302_20100114_053835 CNES's offline processing software has been updated this week to the same V3.0 core processing (SPA component) as TM-NRT-V3. The minor anomalies listed above will therefore also be corrected in the V3.0 IGDRs and GDRs.
Operationally, the last IGDR produced with SPA-V2.3 was:
JA2_IPN_2PcP056_226_20100117_044720_20100117_054333 and the first IGDR produced with SPA-V3.0 was:
JA2_IPN_2PcP056_227_20100117_054333_20100117_063946 Today CNES has reprocessed the IGDRs for cycle-056 passes 148 to 245 to be consistent with the OGDR products based on TM-NRT-V3. These V3.0 IGDRs will be available via AVISO and CLASS shortly. Finally, the GDRs for cycle-052 and beyond will be produced with SPA-V3.0. The latest cycle-051 GDRs were produced with SPA-V2.3, and will be released shortly.