Validation practices for satellite-based Earth observation data across communities

Abstract

Assessing the inherent uncertainties in satellite data products is a challenging task. Different technical approaches have been developed in the Earth Observation (EO) communities to address the validation problem which results in a large variety of methods as well as terminology. This paper reviews state-of-the-art methods of satellite validation and documents their similarities and differences. First, the overall validation objectives and terminologies are specified, followed by a generic mathematical formulation of the validation problem. Metrics currently used as well as more advanced EO validation approaches are introduced thereafter. An outlook on the applicability and requirements of current EO validation approaches and targets is given.This work has received funding from the EC FP7 Quality Assurance for Essential Climate Variables (QA4ECV) (grant agreement 607405) Project for the preparation of the Copernicus Climate Service, and the EC Horizon 2020 project GAIA-CLIM (grant agreement 640276). Parts of the work were also supported through the ESA Climate Change Initiative (CMUG and GHG-CCI) and the European Commission’s eartH2Observe Project (European Union’s Seventh Framework Program, grant agreement 603608)