Code sequence synchronisation for SAR radiometric calibration

Code sequence synchronisation in active coded transponder (ACT) is very important in the process of SAR radiometric calibration. According to the principle of coded SAR radiometric calibration, a signal processing model of active coded reflected signals is proposed in this paper. By means of three cyclic steps, correlation property of pseudorandom code sequence is used for code sequence synchronisation which is divided into two steps: coarse timing synchronization and fine timing synchronization. Simulation experiments with the compression of SAR azimuth signals are carried out. Finally, based on the experimental results, this paper proposes a new method of code sequence synchronisation for SAR radiometric calibration.