This page is the entry-point for the Level-2 ATBDs (Algorithm Theoretical Basis Document) produced by the ESA CIMR DEVALGO study.

The CIMR DEVALGO study is a 2-year ESA-funded study (2022-2024) funded to develop prototype ATBDs for a selection of CIMR Level-2 products.

The Level-2 ATBDs developed by the CIMR DEVALGO study, sorted by Level-2 Product families, are:

• Polar Regions and Adjacent Seas:
  • Level-2 Sea Ice Concentration, Sea Ice Edge, and SIC in NRT1H v1
  • Level-2 Sea Ice Drift v1
  • Level-2 Sea Ice Thickness v1
  • Level-2 Sea Surface Temperature v1
  • Level-2 Sea Surface Salinity v1
  • Level-2 Ocean Wind Vectors v1
• Global Land:
  • Level-2 Terrestrial Snow Area v1
  • Level-2 Soil Moisture v1

In addition, a Multi-Parameter Retrieval for Polar Ocean, Sea Ice, and Atmosphere variables v1 ATBD is developed.

⚠️ Pre-requisite (for Level-1B) : Our Level-2 ATBDs (specifically the SSS and OWV ATBDs) also describe relevant TB correction algorithms that will eventually be implemented in the Level-1B (and not at Level-2). We include these steps as a reference, but they shall eventually be defined in the CIMR Level-1B ATBD. These include but are not limited to:

• Corrections for the sky and Sun direct and Earth reflected/scattered radiation (L-band) [Sunglint in ATBD] and [Sky/Galaxy in ATBD];
• Faraday rotation across the ionosphere (L-band) [link to the ATBD];
• Rotation of the Stokes parameter from the antenna polarization basis to the surface polarization basis (all bands) [link to the ATBD];
• RFI detection, filtering and mitigation (all bands).

Repositories holding the content of the ATBDs are at the bottom of this page.

CIMR is the Copernicus Imaging Microwave Radiometer mission, a multi-frequency, conically-scanning passive microwave imager designed by ESA to support EU's Arctic Policy, among others. Its launch is scheduled in 2029. More info about CIMR here and here.

CIMR DEVALGO develops selected CIMR Level-2 ATBDs in the form of jupyterbooks. The aim of the study is to:

Provide baseline Level-2 retrieval Algorithm Theoretical Baseline Documents (ATBD) - and supporting prototype software and validation data - for the CIMR Mission.

ATBDs are developed in two stages:

• v1 ATBDs describe the selected algorithm and expected input/output data streams.
• v2 ATBDs further describe the algorithm, add an open-source software prototype of the algorithm, and perform performance evaluation.

The figure below gives a general concept for the suite of DEVALGO ATBDs:

The DEVALGO team is led by Thomas Lavergne from the Norwegian Meteorological Institute (NO). The consortium partners are the University of Bremen (DE), the Danish Meteorological Institute (DK), IFREMER (FR), and the Finnish Meteorological Institute (FI).