Crashing waves in the ocean

New Sentinel-3 Altimetry Processing Baseline Collection 005


Crashing waves in the ocean
Crashing waves in the ocean

The Processing Baseline (PB) SM__WAT.005.01 is the first of the new Baseline Collection 005 (BC 005). It provides a large evolution of Sea Level, Wind and Waves with increased quality.

Last Updated

07 July 2022

Published on

23 June 2022

This PB becomes operational on 7 July 2022 and brings several relevant evolutions and anomaly fixes to the Sentinel-3 altimetry marine products.

Since this PB introduces a large shift in the geophysical retrievals timeline, it is part of a new Baseline Collection. Full mission reprocessing is currently underway, to allow for a fully consistent timeline.

The updates impact both Level-1 and Level-2 products.

Naming convention

With this new PB, a new naming convention is introduced.

  • SM__WAT.005.01.00 (SRAL/MWR L2 Marine)
  • SR__L1M.005.00.00 (SRAL L1 Marine)
  • MW__L1_.005.00.00 (MWR L1 Global)

The first seven characters refer to the processing chain/product type, followed by the Baseline Collection, then the processing baseline (incremental) and finally the patch number (incremental). All the fields are separated by point. This information is now part of the products (both netCDF and manifests).

Unless specifically mentioned the usage of the SRAL/MWR L2 Marine PB name contains all the changes for both L1 and L2 and allows to aggregate in a simplified way all these changes.

SRAL/MWR L2 (v7.01)

  • Updates to the SSHA
    • New Mean Sea Surfaces
      • Combined MSS, CNES/CLS15, SIO, DUT15 (new default MSS)
      • DTU21 (including accuracies information)
    • New Pole Tide solution (Desai 2017).
    • Internal tides and long tide non-equilibrium now applied to calculate SSHA.
    • Dynamic Atmospheric Correction (DAC/MOG2D) available in NRT and applied to the SSHA.
    • New Sea State Bias (Tran 2021) derived from S3A SAR/PLRM for Ku-band.
    • Real Zero Masking from L1B data applied at SAR L2 (all timeliness).
    • Range Walk (applied at SAR L1, only NTC).
  • GPD+ Wet Tropospheric Correction available for NTC timeliness (not yet applied to the SSHA).
  • More information to the user:
    • Processing Baseline; All system bias; etc.
  • No-more (land-)ice variables being generated by Marine products.
  • Wind and Waves: Updates to mean values of SWH and Wind Speed due to Range Walk, Zero Masking and system bias updates for better alignment

SRAL L1 (v6.23)

  • Correction of USO reading (relevant for all S3B data).
  • Removal of CAL2 application to CAL1.
  • CAL1 range correction generated using CoG (centre of gravity) method.
  • New CAL2 normalization, by plateau instead of max
  • Range Walk correction is now applied to SAR mode (NTC only currently).

MWR L1 (v6.13)

  • Improvements to data processing during Moon calibration events.

Overall impact

Detailed impact on Sea Level, Winds and Waves to be provided shortly.

More details can be found in the product notice and product format specifications on the Altimetry resources page.

For more information, contact our User Service Helpdesk.