Validation of soil moisture retrieval algorithms from Sentinel-1 data

ESA SEOM Exploit-S-1 - Exploitation of Sentinel-1 for Surface Soil Moisture Retrieval at High Resolution

Founded by: European Space Agency
Duration of the project: 2016 – 2020

Project leader: CNR-IREA (Italy)
Francesco Mattia,

Ludwig Maximilian University of Munich (Germany)
Gamma Remote Sensing Research and Consulting AG (Switzerland)
Institute of Geodesy and Cartography:
Prof. K. Dabrowska-Zielinska,
Dr. Jan Musial,

Main objective:

The scope of the Exploit-S-1 project was to demonstrate the capabilities of the S-1 mission to support systematic SSM product generation at high resolution (e.g. 500m-1000m) and at regional/continental scale.

Task description:

A suite of SSM retrieval methods have been developed, implemented and validated using S-1 data. The methods have been based on previous research into C-band soil moisture retrieval and selected from the great wealth of approaches proposed in the literature and tailored to S-1 data. The emphasis has been on implementing and comparing algorithms presenting the most promising trade-off among robustness, retrieval accuracy and potential matching with the requirements of different applications (e.g. Numerical Weather Prediction, hydrological forecasting, drought events …) in terms of accuracy, resolution and product frequency. In addition, the suitability of the algorithms to fully exploit the S-1 observational assets (e.g., dual polarization, spatial/temporal resolution, radiometric accuracy) in order to deliver a large scale mapping has been considered.

A key component of Exploit-S-1 has been the validation activity that included local and regional scale sites (e.g. the Mediterranean basin) in order to better assess the potential for pre-operational and operational soil moisture products and services.

A further pivotal element of Exploit-S-1 has been the assessment of the optimal pre-processing of S-1 time series for SSM retrieval which will also have the outreaching effect of consolidating standards for the generation of S-1 multi-temporal products that are well suited for other S-1 retrieval studies.

Expected results:

  • Review of application requirements and soil moisture retrieval algorithms.
  • Development of selected SAR soil moisture retrieval methods having the highest potential to meet the application requirements and enable a Sentinel-1 large scale mapping.
  • Validation of the retrieval algorithms at local and regional scales.
  • Provide a scientific roadmap for future Sentinel-1 exploitation for soil moisture retrieval.

Official project website:
Project website under ESA SEOM: