ERS SAR Wave Mode Mission Reprocessing Update

ESA is currently at the final stages of consolidating the complete set of ERS-1 and ERS-2 Wave Mode data into a common format with a uniform retrieval methodology inherited from ENVISAT ASAR. Due to the differences between the sensor systems, methods and retrieval algorithms have been adapted and optimised to process ASAR-like products generated from the raw ERS data. Three data products have been produced:

• WVI : single look complex imagettes, generated with MDA processor ASAR/5.03L03
• WVS : image cross spectra, generated with MDA processor ASAR/5.03L03
• WVW : ocean wave directional spectra, generated with CLS/Norut/Ifremer processor 2.0.

Processing schedule

Processing has been undertaken by the French Processing and Archiving Facility (F-PAF), hosted at IFREMER / CERSAT. This reprocessing campaign covers the ERS-1 mission from 31 July 1991 (orbit 213) to 28 April 1996 (orbit 25036), and ERS-2 from 03 October 1996 (orbit 2364). Along with ENVISAT ASAR Wave Mode data, the ERS data will enable global wave mode analysis to be performed covering a period of over 20 years.

Initial processing of all ERS-1 data and ERS-2 data from 03 October 1996 to 17 January 2001 is almost complete. ESA is now undertaking processing of the ERS-2 data from January 2001 onwards which, as it was collected in no-gyroscope mode, required the use of a new processor.

Data access

The reprocessed WVS and WVW will be made progressively available from the F-PAF server (ftp://eftp.ifremer.fr). Due to their large size, WVI products will not be available as FTP downloads, rather they can be supplied on USB hard disks on request through the ESA EO helpdesk.

Access to the reprocessed ERS SAR Wave Mode data can be provided to existing ESA proposals and/or Registrations by contacting the EO Helpdesk or through a new Registration on the ESA EOPI Portal.

Quality assessment & GlobWave access

In order to support the reprocessed data quality assessment and validation, ERS-1 and ERS-2 Wave Mode products are systematically produced with co-located sources of information, namely:

• Wave Watch III model run at Ifremer on global ocean. Spectra from the model are extracted at each Wave Mode product location.
• In situ buoy measurements from NODC, CDIP and MEDS buoy networks.

As part of ESA GlobWave objectives, these reprocessed satellite L2P datasets and in situ data matchups will be made available through the GlobWave portal in early 2012. As with all GlobWave products, these datasets will be provided in the netCDF format.

Further information

More details of the ESA SAR Wave Mode Mission Reprocessing can be found here