J4 ›› 2014, Vol. 41 ›› Issue (3): 56-62.doi: 10.3969/j.issn.1001-2400.2014.03.009

• Original Articles • Previous Articles     Next Articles

Novel signal processing approach for squint beam-steering SAR (BS-SAR)

WU Yufeng;SUN Guangcai;XING Mengdao;BAO Zheng   

  1. (National Key Lab. of Radar Signal Processing, Xidian Univ., Xi'an  710071, China)
  • Received:2013-09-02 Online:2014-06-20 Published:2014-07-10
  • Contact: WU Yufeng E-mail:wyf1176@163.com

Abstract:

Due to the severe coupling effect between range and azimuth and the aliasing in the azimuth-frequency domain, it is difficult to deal with the squint Beam-Steering Synthetic Aperture Radar (BS-SAR) signal. Although the linear range walk correction can decrease the coupling effect dramatically, it leads to azimuth-variation into the Doppler frequency modulation (FM) rate and range cell migration (RCM). In order to eliminate the azimuth-variation, a novel spectrum processing approach based on azimuth resampling is proposed in this paper. After the linear range walk correction, the azimuth resampling is carried out in the azimuth-frequency domain and the signal’s spectrum will be completely equivalent to the broadside SAR configuration. For squint BS-SAR, the resampling is combined with the SPECAN technique. So the squint BS-SAR signal’s spectrum without aliasing and azimuth-variation can be obtained. Then the signal can be focused by the broadside BS-SAR imaging algorithm. Simulation results show that the proposed approach can be used to process squint BS-SAR data effectively.

Key words: squint beam-steering SAR (BS-SAR), azimuth resampling, linear range walk correction, equivalent broadside processing