GOFC-GOLD Support to CEOS Calibration Validation WG

Background

The CEOS Calibration Validation Working Group (CVWG) to The CEOS Working Group on Calibration & Validation (WGCV) is one of the three standing working groups of the Committee on Earth Observation Satellites (CEOS). The objective of the initiative is “to enhance coordination and complementarity, to promote international cooperation, and to focus activities in the calibration and validation of Earth observations for the benefit of the CEOS members and the international user community” (CEOS WGCV).

The Working Group is structured in several subgroups. The specific objectives of the Land Product Validation (LPV) Supgroup are:

• Foster quantitative validation in a traceable way of higher level global land products derived from remote sensing data and relay results so they are relevant to users,
• Increase the quality and efficiency of global satellite product validation via developing and promoting international standards and protocols for field sampling, scaling, error budgeting, data exchange,
• Provide feed-back to international structures (GEO/GEOSS) concerning requirements and achievements on product accuracy and quality assurance and on definition of future missions.

GOFC-GOLD Contribution

The GOFC-GOLD land cover implementation team and the CEOS land validation subgroup have been working on developing and implementingt a land cover harmonization and validation framework. These joint activities between the CEOS Cal/Val group and the GOFC-GOLD LC-IT have received a further push during the CEOS Cal/Val meeting 2008 in Avignon and the 3rd GOFC-GOLD Land Cover Symposium 2008 in Jena.

Among the ongoing activities are the prototyping of comparative global land cover validation exercises using the existing GLC2000 reference database. Such activities are technical precursors to the implementation of an operational global land cover validation system that is key component of observing land cover as ECV. Such technical efforts are part of a number of near term priorities:

• Continued cooperation between GOFC-GOLD and the CEOS land Cal/Val subgroup and support of international projects,
• Utilize and make available existing global reference databases (i.e. from GLC2000 and GLOBCOVER projects),
• Define standard accuracy assessment for fine-scale land cover change and area estimates,
• Planning and foster implementation for an operational validation component of global land cover monitoring (i.e. ECV),
• Use of “application specific weighting” for accuracy reporting to link land cover observations to areas of societal benefits,
• Continued communication and dedicated contributions with political and policy level including the UNFCCC/SBSTA and GEO (work plan tasks).

Figure: Deriving probability maps of individual map products and classes based on comparative validation towards a joint “best” map estimate.

Best Practices document:

Strahler, A., Boschetti, L., Foody, G. M., Fiedl, M. A., Hansen, M. C., Herold, M., Mayaux, P., Morisette, J. T., Stehman, S. V. & C. Woodcock (2006): Global Land Cover Validation: Recommendations for Evaluation and Accuracy Assessment Of Global Land Cover Maps, Report of Committee of Earth Observation Satellites (CEOS) - Working Group on Calibration and Validation (WGCV).

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