On 20 September 2021, the new CryoSat Ice Baseline-E processors were installed into operations within the CryoSat Payload Data Segment (PDS). This major processor upgrade concerns both the Ice Near Real Time (NRT) and Offline processing chains with data validity starting 22 August 2021 and brings with it improvements to all CryoSat Ice products. The Baseline-E processors were approved for installation following validation and quality checks from expert teams.

Baseline-E evolutions include:

• Improved filtering of outliers to improve interpolated SSHA accuracy over the sea ice.
• Improved interpolation of SSHA across file boundaries and mode changes, using data from adjacent files.
• Provision of an improved snow depth correction, through modification of Warren Snow Depth according to sea ice type
• Addition of 20Hz Pseudo-LRM (PLRM) estimates to the L1B SAR and SARIn products.
• Improvements to LRM and SARIn land ice retracking
• Compression of the L1B & L2 netCDF products
• Generation of new L1B Stack (L1B-S) product (available to specialist users on demand only).
• Implementation of updated Earth Explorer CFI software library, allowing correct handling of Doris Navigator Orbit files.
• Resolution of several known anomalies in Ice Baseline-D products.

Baseline-E NRT include:

• Resolution of NRT orbit usage inconsistencies. At Baseline-D approximately 5% of NRT products are processed with the back-up FOS Predicted Orbit file (MPL_ORBPRE) instead of the preferred DORIS Navigator Orbit file (DOR_NAV), causing inconsistencies in altitude measurements and all derived parameters. At Baseline-E, the implementation of a new orbit selection policy, and the updated Earth Explorer CFI software library will allowing the correct handling of Doris Navigator Orbit files for NRT products and reducing the number of processing failures.

All data are accessible via the CryoSat Science Server. To make room for Baseline-E products, the old Ice_Baseline_C directory has been removed from the CryoSat Science Server and all Ice Baseline-D products have been moved to the Ice_Baseline_D directory.

The first version of Baseline-E documentations can be found on the CryoSat Data page. Additional documents will be released in the coming weeks.