Soil moisture scientists had the opportunity to train with an ESA validation service at a recent workshop. The tool, which is highly rated by the CEOS Working Group on Calibration and Validation, provides valuable support for validating data.

For almost 15 years, the global soil moisture community has gathered every two years to discuss the latest scientific progress regarding the validation and application of soil moisture products from Earth observation satellites.

The latest meeting, the Seventh Satellite Soil Moisture Validation and Application Workshop, took place from 4 to 6 June at Michigan State University in East Lansing, Michigan, USA. Over 50 international participants attended the workshop.

At the workshop, Alexander Gruber (FRM4SM Science Lead) and Wolfgang Preimesberger (QA4SM Core Developer) introduced the latest release of the Quality Assurance for Soil Moisture (QA4SM) framework, which is developed as part of ESA’s Fiducial Reference Measurements for Soil Moisture (FRM4SM) project.

QA4SM is a cloud-based online service that allows users to validate soil moisture products using the best available Fiducial Reference Measurements (FRMs) with the latest community-agreed best practice guidelines.

The service makes uncertainty assessment easy, standardised, reproducible, and does not require users to store their products locally. It also provides several additional features for both satellite data users and producers, including archiving validation results and metadata on zenodo with DOI- based citations, sharing and directly comparing validation results, and a new feature will soon allow for generation of automated validation reports for systematic tracking of satellite product performance across epochs and algorithm versions.

During the workshop, participants attended an interactive training session with QA4SM. Trainees completed a survey after the session, where they reported that prior to the workshop most attendees had used their own tools for validation and stored data files locally. After the training, they agreed that QA4SM is an invaluable tool for the soil moisture community, enabling easy evaluation of datasets they have created and performing in-depth analysis of the state-of-the-art datasets openly available from missions such as ESA’s Soil Moisture and Ocean Salinity (SMOS) and NASA’s Soil Moisture Active Passive (SMAP). They also cited QA4SM’s automated monitoring of operational soil moisture data products as an important asset.

The potential of QA4SM has been recognised by the Committee of Earth Observation Satellites (CEOS). FRM4SM’s efforts toward enabling systematic, automated, and traceable FRM-based validation of soil moisture products and the tools provided by QA4SM, recently motivated the CEOS Working Group on Calibration and Validation to promote soil moisture products to the highest stage in the CEOS validation hierarchy. This classification - Validation stage 4 - means that soil moisture product validation is now recognised as among the most sophisticated of all land Cal/Val activities.

Go to QA4SM today to start using this internationally recognised soil moisture validation service.