Research on Time and Frequency Synchronization Technology of Space-surface Bistatic SAR

This paper researches the estimation method of the time and frequency synchronization errors of SS-BisSAR (Space-surface Bistatic SAR) based only on the direct signal and discusses the estimation precision. Firstly the model of direct signal is built and analyzed and the traditional method to estimate the Doppler centroid frequency is modified to fit the case in SS-BisSAR and in this way, the estimation method of synchronization error is proposed. Finally the relation between the SNR of signal and the estimation precision is derived and analyzed. The conclusion shows that, only utilizing the direct signal, the estimation method is feasible. As the precision of estimation is affected by the SNR, carrier frequency and signal bandwidth, etc. So, the system parameters should be reasonably designed to realize a high precision estimation in order to compensate the errors and improve the imaging quality of SS-BisSAR.