7. Changes#

This sections summarizes the main changes with respect to the previous releases.

7.1. version 4 [2024/2025]#

The version 4 extends the version 3 dataset up to December 2023 and fixes some minor issues or add some additional ancillary variables.

Version 4 extends the altimeter data series of version 3 with 3 more years up to 31-Dec-2023 for the ongoing (Jason-3, SARAL, Cryosat-2) and newest (Sentinel-3 A, Sentinel-3 B, Sentinel-6 A) but also backward by adding more missions (ERS-1, ERS-2, Topex-Poseidon) back to 1992.

Version 4 also adds SAR altimetry data from Sentinel-1 A and Sentinel-1 B Image mode (IW and EW).

7.1.1. L2P products#

7.2. Version 3 [2021/2022]#

The version 3 extends the version 2 dataset up to December 2020 and fixes some minor issues or add some additional ancillary variables. Version 3 also adds SAR altimetry data from Sentinel-3, and microseism data.

7.3. Version 2#

The 2nd version (version 2) of CCI Sea State products provided a complete revised processing and methodology compared to the version 1 which was mainly inherited from the GlobWave project. It extended and improved the altimeter significant wave height (SWH) products which were a post-processing over existing L2 altimeter agency products with a complete new retracking of the considered missions for this version 2, and fully revised filtering, corrections and uncertainty evaluations. The retracking of altimeter waveforms was performed with two different retrackers: WHALES by TUM for LRM altimeters,
and LR-RMC by CLS/CNES for SAR altimeters. Because of the novelty of this approach and the required processing effort, this was only applied to a limited set of recent altimeters spanning from 2002 to 2018.

7.4. Version 1#

The version 1 was mainly inherited from the GlobWave project.