SPAR@MEP aims to derive a consistent Aerosol and Surface Reflectance long-term data record in the PROBA-V Mission Exploitation Platform (MEP) based on SPOT-VEGETATION and PROBA-V observations. The project deliverables will consist on a Long Term Data Record (1998-2018) of Aerosol Optical Thickness (AOT) and Bidirectional Reflectance Factor (BRF) at 1Km of resolution over selected key macro regions around AERONET stations and on a global processing of about 5 years at a spatial resolution suitable for climate studies (e.g., 5km). The target processing facility will be the Proba-V MEP. The radiometric accuracy and multi-temporal stability of the considered long-term data record, which was acquired with three different radiometers (SPOT-4, SPOT-5 and Proba-V), should be carefully assessed as a first verification step for the project. Furthermore, the processing performances should be significantly improved in order to sustain the mission reprocessing. To this end, the current plan is to exploit multi-cores CPU, or, alternatively, the GPU technology. Both parallel processing with CPU multi-cores and GPU servers are available on the MEP to support this project.

The comprehensive PV-LAC feasibility study demonstrated the possibility to apply the CISAR algorithm on PROBA-V data for the joint retrieval of surface reflectance and aerosol optical properties. On top of that, under the context of the CIRCAS study the CISAR algorithm has been modified to also retrieve cloud optical thickness and can therefore can be run without the need of an external cloud mask.



Progress meeting 1

The first progress meeting will take place at Brussels on the 22/01/2020. A technical meeting will follow the 23/01/2020 at VITO.


Kick-off meeting

The SPAR@MEP kick-off meeting took at ESRIN (IT) on the 06/09/2019.





Rayference has been created in 2013 as a private business company (SME) by Yves Govaerts and provides advanced technical and scientific expertise on Earth Observation, more specifically in the area of radiative transfer, inverse modelling, vicarious calibration and fundamental and thematic climate data record generation. Rayference contributes to the preparation of new space missions in the area of air quality and global surface monitoring. It is also involved in climate monitoring research projects and the design of algorithms for the operational retrieval of geophysical products. Rayference is a member of the CEOS IVOS working group.

Rayference project activities include:

  • Project Management
  • Algorithm Evolution
  • Product Generation and Validation
  • Outreach and Publication

Key personnel


Yves Govaerts

Project Manager / Scientific Advisor


Marta Luffarelli

CISAR algorithm prototyping


Sotiris Sotiriadis

GEDAP update and product validation


Send us a message