The FIDelity and Uncertainty in Climate data records from Earth Observations (FIDUCEO) project Sea and Lake Surface Temperature Climate Data Record core retrieved quantity is the skin (radiometric) temperature of the Earth’s water surfaces (sea and large lakes). This is provided as a best estimate, plus an ensemble of 10 perturbations capturing known uncertainties. The CDR contains grid-cell instantaneous averagesof retrieved surface temperature over ice-free oceans and 300 large lakes.

The FIDUCEO Surface Temperature CDR differs from the ESA Sea Surface Temperature Climate Change Initiative CDRs ; which were generated using in the using the same cloud detection and SST retrieval methodology in the following points:

- The calibration of the brightness temperatures used is revised for the FIDUCEO ST CDR. The first step in this has been multi-sensor harmonisation to obtain baseline calibration coefficients (Giering et al., 2019). For specific ST application, these coefficients were adjusted such that SSTs had lower bias, using a method of cross-referencing to matched drifting buoys (Merchant et al., 2019)
- Perturbations to the obtained ST and quality level determination are provided for an ensemble of 10 members, for the purpose of propagating uncertainty in ST in complex (large scale, non-linear) applications.
- The FIDUCEO ST CDR includes retrievals over the world’s 300 largest lakes, unlike the SST-only product. (Lakes, including much smaller lakes,are addressed in other CDRs requiring significantly different methodsto cope with the difficulties of small target water bodies.)

Full documentation including product user guide, tutorials, the scientific basis and relevant publications are available in the documentation.