A Phase Synchronization Approach for Bistatic SAR Systems
Conference: EUSAR 2006 - 6th European Conference on Synthetic Aperture Radar
05/16/2006 - 05/18/2006 at Dresden, Germany
Proceedings: EUSAR 2006
Pages: 4Language: englishTyp: PDFPersonal VDE Members are entitled to a 10% discount on this title
Wang, Wenqin; Liang, Xingdong; Ding, Chibiao; Wang, Yanping; Hong, Wen (National Key Laboratory of Microwave Imaging Technology, Institute of Electronics, Chinese Academy of Sciences, P. R. China)
Wang, Wenqin (University of Graduate, Chinese Academy of Sciences, No. 19, BeiSiHuanXiLu, Beijing, 100080, P. R. China)
The requirements imposed on bistatic SAR systems have increased steadily. Directly associated with these requirements one has to solve the problem of highly accurate time and phase synchronization. This paper concentrates on the oscillator frequency instability between bistatic transmitter and receiver. An analytical model of phase noise is presented, in which Gauss noise is used as the input of a hypothetical low-pass filter and its output is considered as phase noise. Simulated results show that oscillator frequency instability may not only defocus the SAR image, but also introduce significant positioning errors along the scene extension. To obtain focused bistatic SAR image, phase synchronization must be ensured. Then one method of phase synchronization is presented, in which we use the direct-path echo as one reference signal to compensate the phase error caused by oscillator frequency instability. Finally, some recommendations for future work are given.