#brdf
This is main program to allow data extraction in the context of BRDF exercise
-Description of including files :
-- global_variables       -> Class to define env variables.
-- Test_esa_s3_read       -> Script to show handling of S3 data
-- Test_vito_probav_read  -> Script to show handling of PROBAV data
-- libs
    --- rios               -> Image processing librairy
    --- log                -> Class to handle font for logging message
    --- esa_s3_data        -> Class defining S3 processing
    --- vito_proba_data    -> Class defining PROBA V processing
    --- convert_to_toa     -> Generic function to apply toa conversion
    --- gdal_geocoded      -> Generic class based on gdal for geometry
    --- gdal_clip          -> Well known gdal command on board
    --- gdal_merge         -> Well known gdal command on board

- Description of supported product / missions and approach
-- Sentinel 3
--- Import with SNAP, read envi file with GDAL and then
    apply toa conversion with 'rios' lib.

-- PROBA V
--- Format : http://aida.vgt.vito.be/sites/default/files/PROBAV-Products_User_Manual_v2.1.pdf