The Ocean Waves Thematic Data Products (TDP) are taking into account the improvements made in the frame of the REAPER project, the ENVISAT reprocessing 3.0, the CMEMS Sea Level TAC, ESA Sea-State CCI.

The Ocean Waves Thematic Data Products will propose Level 2+ global product at 5Hz with a common product definition. An uncertainty value will be computed for each measurement.

Data Access

A test dataset (two full cycles of ENVISAT data) is available via ftp :

FTP adress :ftp.cls.fr
Login :FDR4ALT
Password: Sent separately

Ocean Waves TDP is available under /Test Data Set/TDP_WA/

Please contact fpiras@groupcls.com to obtain the password.

Official products will be released at the end of the project (March 2024)

Processing & Algorithms

This section contains preliminary results and does not contain all expected improvements. It will be completed and enhanced during the life of the project. 

Retracking Algorithm : Adaptive (ENVISAT), MLE3 (ERS)

Filtering algorithm : HFA (High-Frequency Adjustement) and/or EMD

Editing strategy : Iterative filtering

Format :

This product is light, without groups and contains 8 variables of interest for the ocean waves .

Improvements compared to existing products

One of the most important improvement brought by the FDR4ALT products is the application of the Adaptive retracker on ENVISAT :

The FDR4ALT ENVISAT products show a large reduction of the SWH noise level with respect to the MLE3 20Hz especially below 50km thanks to the Adaptive retracker. In addition, a method derived from Zaron et al. (2019) and Tran et al. (2021) enables to remove the high frequency errors correlated with SLA noise (Adaptive + HFA).

Combined with a flagging and compression method, the SWH estimations from the FDR4ALT products have a better resolution (5Hz compared to the CCI Sea State 1Hz), are less noisy and approch efficiently the coasts with respect to CCI (WHALES) and CCI + EMD. They also enable to better characterize the 10Hz bump, related to wave groups in the case of large swels (>200m) (Adaptive + (HFA) + EMD)

People in charge :

CLS : aollivier@groupcls.com

Documentation : 

Benefits of the Adaptive Algorithm for Retracking Altimeter Nadir Echoes: Results From Simulations and CFOSAT/SWIM Observations (https://ieeexplore.ieee.org/abstract/document/9385074)