Current Activites

The WGCV undertakes a variety of activities related to the calibration and validation (cal/val) of Earth Observation data. Our current activities focus mainly on the requirements identified by the intergovernmental Group on Earth Observations (GEO) and their goal to achieve a Global Earth Observation System of Systems (GEOSS). To this end, GEO has identified a series of tasks related to calibration and validation in which we play a lead role. Some of our current activities include:


QA4EO – A Quality Assurance Framework for Earth Observation

A Quality Assurance Framework for Earth Observations (QA4EO) Logo

A Quality Assurance Framework for Earth Observations

CEOS has established a quality assurance (QA) strategy to facilitate interoperability of Global Earth Observations systems. This strategy is based upon a set of key operational guidelines derived from “best practices” for implementation by the community.  The QA4EO has been completed and endorsed by CEOS and is recommended for implementation and use throughout the GEO community.

Specific implementation tasks:

  1. Develop and initiate an implementation plan for QA4EO (the latest version of the QA4EO framework and its 10 associated key guidelines can be found via the QA4EO website.
  2. Organise a community workshop to address the implementation of QA4EO
  3. Work with the CEOS Working Group on Information Systems & Services (WGISS) on cal/val data access
  4. Establish outreach activities to promote QA4EO within the user community

Contact: QA4EO Secretariat


 DOME C Experiment

  • Conduct a multi-sensor comparison to evaluate the size of any biases using the Dome C site as a reference standard. This will serve as a pilot for future regular CEOS comparisons over this and other reference sites to ensure data interoperability and to underpin the LSI constellation. The results of the comparison will allow an assessment to be made of the site’s suitability for climate quality calibration.
  • Develop the theoretical basis and standard procedure as part of the QA4EO guidelines for future cross comparisons.
  • Present results and put information on the Calibration/Validation Portal.

Contact: Changyong Cao


 The Calibration/Validation Portal and Post-Launch Test Sites (reference standards)

  • Develop a consolidated worldwide Cal/Val test site database and an appropriate subset of CEOS endorsed reference standards, based on community agreed criteria, to be included in the CEOS Cal/Val Portal.
  • Further expand the Cal/Val Portal in both content and functionality by adding links to QA4EO information and data.

Contact: Alessandro Burini or Philippe Goryl


Radiometric Standards

  • Identify fundamental radiometric reference standards and application methods “best practices” for use in EO (WGCV subgroups).
  • Develop a CEOS/WGCV standards and recommendations handbook as a summary of appropriate QA4EO guidelines and reference standards for instrument calibration. (WGCV subgroups).
  • Following the establishment of CEOS reference standards for post-launch Cal/Val, including the moon, standard deserts and LANDNET test sites, WGCV/IVOS will ensure that the accompanying operational guidelines and coordinates are made available through the GEO/CEOS Cal/Val Portal. This list of standards will be increased to encompass other application areas, e.g. water bodies, following approval by the IVOS team.

Contact: Nigel Fox


Benchmark Mission Coordination

  • Maintain dialogue between UK and USA relating to collaboration and coordination of the benchmark measurement/calibration missions (TRUTHS and CLARREO).
  • Subject to resourcing, an optimisation study will be carried out to define operational and detailed mission/instrument specifications of TRUTHS to establish “strawman” requirements as a basis for identification and collaboration of other CEOS space agencies.

Contact: Nigel Fox


Ground-based Cal/Val Campaign

Obtain support and resources to complement those of ESA to initiate and plan an international cross-comparison of ground Cal/Val support techniques and instrumentation for both IR emitted radiance (SST) and VIS/SWIR reflected radiance (Land).

Contact: Nigel Fox


Reference Test Site Data Collaboration and Comparison

Work with WGCV Subgroup leads to initiate dialogue with instrument owners relating to the collection of calibration data over CEOS-endorsed sites.

  • Ensure collaboration and coordination for the evaluation of the data and the development of the results over comparative sites as a prototype for an operational EO calibration network.
  • Peer-review the results and post them on the Cal/Val Portal.
  • Present information via CEOS/GEO venues and workshops.
  • Publish significant results.

Contact: Nigel Fox, Kurtis Thome, Philippe Goryl or Changyong Cao