News

01.02.2021 14:18 Age: 4 yrs

CFOSAT SWIM data reprocessing in version 5 COMPLETED

Category: News of the CFOsat mission, Website updates

We are pleased to announce that the reprocessing of SWIM data in version 5 is now completed, all data from 25 April 2019 to the current date are now available in the V5.1.2 version.

The main improvements are:

  • The new speckle correction, with the empirical model derived from the observation (see Hauser et al, TGRS 20210 (10.1109/TGRS.2020.2994372) => impact on L1B and L2 products
  • The suppression of the mask on the wave spectra
    => impact on L2 products, the wave spectra is provided for all azimuth,
  • The upgrade of the Modulation Transfer Function -MTF- (specified to obtain the L2 wave spectra and SWH from the off nadir observations). It is changed from MTF1 to MTF3 for which the energy of the directional spectra is normalized so as to be the same as the one corresponding to the nadir significant wave height
    => impact on L2 products : strong reduction of bias for Wave parameter SWH when compared to model or buoys data

A summary on the main processing evolutions and impact in the product quality following the switch from OPER to OP05 product is given in the OSTST 2020 presentation “CFOSAT: SWIM products latest evolutions”
ACCESS TO THE DATA: These data sets are fully open for download. They are available on the two following services (please note that the credentials are different for the two services):

1/ On the ftp server :
The SWIM L1B, L2 and L2P SWH 1Hz Nadir are available on the FTP service for quick access and automatic chains:
Registration: please fill the form on the registration form and select the product "Wave / wind CFOSAT product"; the access will be opened after validation by the Service Desk,
Access: with dedicated credentials (login=email address) directly via the FTP (not supported by all browsers) or via your personal space MY AVISO+  (where you have the access to all your products).
To avoid confusion with the previous processing versions:
-the files are now named "CFO_OP05_SWI_....." instead of “CFO_OPER_SWI_...”,
-the folders are named “swim_XX_op05” instead of “swim_XX_oper
The FTP service is: ftp-access.aviso.altimetry.fr/cfosat
in the folders:
-for SWIM L1B products => swim_l1b_op05 (all files are accessible online)
-for SWIM L2 products => swim_l2_op05 (all files are accessible online)
-for SWIM L2P SWH 1Hz Nadir products => swim_l2p_op05 . Note that the reprocessing is still on-going for these products and should be achieved by Mid-February. The new files will be accessible on the fly.  
2/ On the Aviso+ CNES data Center (https://aviso-data-center.cnes.fr/):
All SWIM products (except L2P SWH 1Hz Nadir) and all SCAT products are available via this archive catalogue
Registration: Dedicated credentials used for this service are given via the registration on top/right of https://aviso-data-center.cnes.fr/ ; the access will be opened after validation by the Service Desk,
Access: with dedicated credentials on https://aviso-data-center.cnes.fr/; Note that the archiving of the new version is still on-going and this new version can be identified in the parameter FILE_CLASS where you can choose “op05”
The validation reports can be downloaded here.
Please, contact the help desk at aviso(at)altimetry.fr for any question.
Jean-Michel Lachiver, Cedric Tourain, Lotfi Aouf and Daniele Hauser

Link to CFOSAT mission