The External Calibration System of GF-3 Satellite

In order to guarantee high data accuracy and quality of Chinese GF-3 SAR satellite, external calibration system has been established. This paper describes the constitution and technical concept for external calibration system of GF-3. The external calibration system includes calibration site located in Inner Mongolia, 5 polarimetric active radar cali-brators and 20 passive calibrators. The external calibration system has been used for the in-orbit calibration campaign after the launch of GF-3.