Quality Assurance for High Spatial and Temporal Resolution Soil Moisture Data

Short Description

Starting point / motivation

The Quality Assurance for Soil Moisture (QA4SM) initiative aims to become the international benchmark service for validating satellite soil moisture products. This has been instigated by the development of an initial version of an online open access automated validation testbed: 

To achieve general acceptance, QA4SM endorses maximum transparency, traceability, and reproducibility. This is facilitated through the use of the latest community-based validation best practices, endorsed by the Committee on Earth Observation Satellites (CEOS) and the Global Climate Observing System (GCOS), the use of open source software, algorithms and reference data (e.g. from the International Soil Moisture Network and ERA5 reanalysis).

The completed first phase of QA4SM focused on developing the initial functionality of the service for a selection of coarse resolution soil moisture products (e.g. from SMAP, SMOS and ASCAT). The QA4SM service is built using the latest cloud-computing technology as offered by the Earth Observation Data Centre.

Contents and goals

The proposed QA4SM-HR project will take QA4SM to the next level on the path to become the international standard by focusing on the following vital areas of evolution:

  1. Facilitation of the online validation of spatial and temporal high-resolution soil moisture data from the Sentinel-1 Copernicus Global Land Service and from the proposed ESA Earth Explorer Hydroterra mission;
  2. Enhancing quality assessment procedures by employing the latest validation standards, as guided by TOPC and CEOS, and expanding them to be deployed in the high-resolution spatial and temporal domains;
  3. While extending QA4SM in these directions we will ensure complete reproducibility and transparency of the validations performed with the QA4SM service and in line with the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. This includes full traceability of inputs and outputs including validation and reference datasets, user selected validation parameters, employed algorithms and validation results.


QA4SM closely collaborates with EO Quality Assurance initiatives in other domains, including ESA QA4EO, C3S EQC, and H2020 FIDUCEO, to jointly exploit synergies and identify gaps. Moreover, QA4SM shall also play a future role in benchmarking activities of the international modelling community (e.g., within CMIP, LS3MIP) by facilitating direct access to and applicability of ground reference data for climate and land surface model evaluation.

With its transparent, community-driven concept, QA4SM has received a strong positive response from international satellite data providers and validation teams, including from ESA, NASA and Copernicus.

Expected results

QA4SM-HR will provide the impetus to permanently establish traceable and transparent quality assurance of soil moisture products in a standard service for open scientific use, and give Austria an internationally leading role in the validation of soil moisture from Earth observation data.

Project Partners


AW Software and Technology GmbH

Project partner

Vienna University of Technology

Contact Address

AW Software and Technology GmbH
Mariahilfer Straße 47/3/1
A-1060 Vienna