Overview of the project

Fundamental Data Records for Altimetry (FDR4ALT) is an ESA project aiming at generating innovative Earth system data records named Fundamental Data Records (basically level 1 altimeter and radiometer data) and Thematic Data Records (basically level 2P geophysical products), in the frame of the European Long Term Data Preservation Program (LTDP+).

These products will be based on the exploitation of measurements acquired by the altimeter and radiometer instruments onboard three remote sensing satellites, ERS-1, ERS-2 and ENVISAT.

The goal is to serve the different communities involved in long term data exploitation over the different Earth surfaces: oceancoastalinland waterice sheetssea ice and atmosphere.

Overview of the FDR4ALT products


ERS-1, ERS-2 and ENVISAT Altimeter and Radiometer dataset have been reprocessed in NetCDF format, based on the best state-of-the-art algorithms/corrections with definition and provision of innovative level-1 and level-2P products including uncertainty information at both levels.

Project Planning

T0 = September 2019

Phase 1 : Processing selection and products definition (completed)

  • Completeness analysis
  • Selection of the algorithms for the FDR & TDP products definition
  • Definition of a validation plan
  • Organisation

Phase 2 : Production and Validation (on-going)

  • Algorithm implementation in the CLS/CNES core system
  • Massive p roduction of the FDR and TDP for the whole dataset (23 years of data)
  • FDR and TDP validation
  • Uncertainty characterization

The Project kicked off on september 2019 and is planned to end in December 2022.

Data Access

The FDR4ALT products are not available yet and will be released at the end of the project (December 2022)