An innovative calibration concept for space SAR using an active antenna with improved efficiency, reliability and radiometric accuracy

Inhalt:
A study has been undertaken by a team lead by Alcatel Alenia Space for ESA/ESTEC concerning innovative ideas and approaches for the radiometric calibration of SAR instruments using active antennas. The first innovation allows the antenna pattern to be fully and accurately characterised by internal measurements or over a single external transponder. The second idea allows the improvement of the determination of the antenna pointing information. Another significant improvement is obtained by using ground calibration transponders incorporating digital processing of the radar signal and transmitting weather data directly to the instrument. The implementation of the calibration BFN and of the radiating surface is also discussed. All the proposed ideas are part of an overall radiometric calibration concept that offers an improved radiometric accuracy with efficiency and cost benefits over current solutions.