PostDoc - Physical Scientist

Météo France

Toulouse, France

Description

The open position is to join the ImagineS (Implementation of Multi-scale Agricultural Indicators Exploiting Sentinels) project of Framework Programme 7 (FP7). This project aims at supporting activities in the domain of agricultural survey and the assimilation of satellite products in a Land Data Assimilation System (LDAS) for monitoring the crop/fodder biomass production together with the carbon and water fluxes. A peculiarity will be the assimilation of surface albedo by merging the information coming from different Sentinel sensors and other COPERNICUS (http://www.copernicus.eu/) contributing missions. The proposed position will consist to develop operational algorithms for generating a global 300m albedo product derived from Sentinel-3 and PROBA-V observations as the continuity of the kilometric products available in near real time and long-time series in geoland2 (http://www.geoland2.eu/ ). Particularly, the candidate will have to develop synergies between the retrieval of surface albedo and of aerosol reflectance components, in order to simultaneously improve the characterization of the aerosols and the estimation of diffuse radiation. The "blue-sky" albedo combines directional-hemispherical reflectance (DHR) and bidirectional-hemispherical reflectance (BHR), depending on the fraction of diffuse fraction. This in fine quantity is the albedo product to be used and validated against ground network observations (FLUXNET or others). Besides, the narrow S3 bands will permit the modelling of the leaf/canopy albedo as a function of chlorophyll, brown pigments, leaf water content, with possible interactions with the parameters of the land surface models (ISBA-A-gs and CTESSEL) used in this project, and the development of a prognostic albedo in ISBA-A-gs. The objectives of the incumbent's activities are to participate to the development of methods:

- Merge Sentinel-3 and PROBA-V data to generate internal BRDF (Bi-Directional Reflectance Distribution Function) products and pre-operational global 300-m Albedo products using the same basic algorithmic principles applied to generate the geoland2 products.

- Integrate a simultaneous removal of surface and aerosol BRDF for a characterization of diffuse radiation.

- Improve accuracy assessment in the computation of broadband albedo quantities, PAR domain inclusive.

-Develop algorithms for separation of soil/vegetation/snow-free albedo.

- Dedicate efforts to provide quantitative uncertainty estimates, which are required for the assimilation of these products within process models.

- Participate to the writing of documents of reference: Algorithm Theoretical Baseline Document (ATBD), Product User Manual (PUM).

The developed algorithms will be transferred to VITO (http://www.vito.be ) which will realize the production of albedo and will also check the consistency of time series to ensure a smooth transition between the improved products. The scientific validation of products will be achieved in collaboration with EOLAB (http://www.eolab.es/ ). The whole procedure of validation will follow the CEOS/LPV guidelines.

Requirements

The candidate should have an excellent knowledge of the language programming (Fortran, C, C++) and should have notions of graphic software (PVWave, IDL, Matlab). It is suitable to have a very good background in remote sensing science, particularly on optical radiation transfer modelling and satellite data processing. The position is opening for post-doctoral and engineers. It must be foreseen travels in order to attend group meetings and workshops, and also to participate to international conferences

More information and applications

Application should be done by email by sending a resume with the list of publications, a letter of motivation, and letters of reference. The net monthly salary will vary between 1,900€ and 3,000€, depending on qualification, for a 17-months contract with a possible extension of 3 to 8 months. This salary is before income tax and includes health insurance. Contact: Jean-Louis Roujean (jean-louis.roujean@meteo.fr), CNRM / Météo-France.