Exploration of candidates ground sites over Algeria to EO satellite vicarious flight calibration purposes

Radiometric performances of Earth Observation Satellite sensors vary between ground pre-launch calibration campaign, after launch and over satellite lifetime due to launching vibration, eventual optical element misalignments, degazin effect and most generally space harsh environment. Due to the inaccessibility of the satellite on orbit, the vicarious calibration method based on a ground site using simultaneous ground reference data is often considered as an essential step to ensure best accuracy tradeoffs. This method has the advantage of reproducing the real conditions of image data acquisition. Its accuracy depends closely on the radiometric stability of the calibration site, site reflectance measurements, and knowledge of the atmospheric parameters during image acquisition. Since, the most used method is the absolute vicarious calibration which deals with the ground site which is popular in the Calibration/Validation community for the accurate characterization (reflectance, spectral, stability) of calibration sites. Characterization of former remains very important because it constitutes the most important contributor to precise sensor calibration and data Quality Assurance. The aim of this work is to assess and evaluate new candidates calibration sites over Algeria in order to explore the possibility to select them as new calibration test sites and to use them in radiometric calibration of the new Algerian high resolution sensors such as ALSA T-2A & 2B (with similar optical camera PAN: 2.5m & MS: 10m).