The PROBA-V mission: image processing and calibration

Abstract

With the launch of PROBA-V (Project for On-Board Autonomy – Vegetation) in 2013, the continuity and availability of global land-coverage data in four multispectral bands are ensured for the SPOT (Système Pour l’Observation de la Terre)-VEGETATION user community. This community has been served for already more than 14 years with high-quality 1 kilometre-resolution data. To guarantee continuation of this high quality over the full lifetime of PROBA-V, an operational processing platform and in-flight calibration algorithms have to be in place, which fully consider the specific PROBA-V platform and instrument design characteristics. Data quality has to be ensured for all available product levels, i.e. from the radiometrically corrected radiance data to the 10 day global synthesis. In this article we first focus on some specific design characteristics, which impose some challenges for data processing and calibration. Next, a technical description is given for all the processing steps such as mapping, cloud masking, atmospheric correction, and compositing. The functioning of the Image Quality Centre (IQC) is described. The IQC is in charge of the assessment of the PROBA-V performance, the analysis of the image quality, and the radiometric and geometric calibration after launch. Finally information is given on the distribution of the various products to the user community.

Acknowledgements

The authors acknowledge the contribution of the teams from Qinetiq Space, OIP, Spacebel, ACS, Trasys. This work was supported by Belspo and ESA (PROBA-V User Segment contract 091669).