SPAR@MEP aims to derive a consistent SPOT-VEGETATION and PROBA-V Aerosol and Surface Reflectance long-term data record in the PROBA-V Mission Exploitation Platform (MEP). The projects deliverables will consist on a Long Term Regional Data Record of Aerosol Optical Thickness (AOT) and Bidirectional Reflectance Factor(BRF) at 1Km of resolution over Europe for year 2019 and on a global processing of the entire Vegetation/PROBA-V archive at a spatial resolution of 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 conxtext 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.



Webstory: Ship trails in the Biscay Bay

A webstory has been published on ESA website on the aerosol retrieval from PROBA-V observations in the framework of the SPAR@MEP project. The webstory focuses on the retrieval of ship trails from PROBA-V images at 1km resolution with the CISAR algorithm. This interesting case study demonstrates the capability of the CISAR algorithm to correctly differentiate between fine and coarse mode. Also, processing both aerosols and clouds, the CISAR algorithm could represent a powerful tool to study aerosol-cloud interactions, such as the Twomey effect, using high resolution satellite imagery. The webstory can be found at: https://earth.esa.int/eogateway/news/ship-trails-in-the-bay-of-biscay-observed-using-proba-v-imagery. proba-v_biscay


Mid Term Review

The Mid-Term Review (MTR) took place virtually via Webex on the 29th of September. First results of the LTRDR have been presented, obtained with the latest version of the CISAR algorithm, which includes the processing of cloudy pixels. A webstory will be published to advertise these results. The project duration has been extended by 6 months.


Progress meeting 2

The second progress meeting took place virtually on the 26th of May 2020. During the meeting the results on the calibration study on PROBA-V performed by Rayference have been presented, and they will be shown at the next PROBA-V Quality Working Group. The date of the Mid-Term Review has been fixed to September 29th.


Technical meeting

A technical meeting between Rayference and VITO took place at VITO premises on the 23rd of January 2020. During this meeting, the technical aspects of GEDAP implementation in the MEP have been discussed, together with the necessery resources to allocate for the project.


Progress meeting 1

The first progress meeting took place in Brussels on the 22/01/2020. The first milestone was successful with the deliverable of the surface reflectance dataset. During PM1, it has been decided to generate the Long-Term Regional Data Record (LTRDR) over Europe at 1 km resolution and the Global Dataset at 5 km resolution for the full Vegetation-PROBA-V archive. The next progress meeting will take place on the 26th of May 2020.


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


Lucio Franceschini

GEDAP update and data processing


Marta Luffarelli

CISAR algorithm prototyping


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