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ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2016, Vol. 37 ›› Issue (5): 1614-1621.doi: 10.7527/S1000-6893.2015.0325

• Electronics and Control • Previous Articles     Next Articles

A ground moving target parameter estimation method in spectrogram for FMCW SAR

LIANG Ying1,2,3, ZHANG Qun1,2, WU Yong4, GU Fufei1, YANG Qiu1   

  1. 1. School of Information and Navigation, Air Force Engineering University, Xi'an 710077, China;
    2. Collaborative Innovation Center of Information Sensing and Understanding, Xi'an 710077, China;
    3. Unit 95980 of PLA, Xiangyang 441100, China;
    4. Shaanxi Institute of Metrology, Xi'an 710065, China
  • Received:2015-06-08 Revised:2015-07-22 Online:2016-05-15 Published:2015-12-21
  • Supported by:

    National Natural Science Foundation of China (61471386)

Abstract:

The ground moving target parameter estimation method for frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR) is studied. The displaced phase center antenna (DPCA) technique is utilized to cancel the ground clutter, then the influence of the platform and target continuous movement to the echo are analysed, and the relationship between slow time envelope (STE) term and ground moving target parameter is deduced. On this basis, a ground moving target parameter estimation method in spectrogram is proposed. Firstly, the Radon transform is utilized to estimate the equivalent across-track velocity which leads to the range walk, and then the range walk is corrected. Secondly, amplitude of the received signals is extracted from spectrogram, and the change of the amplitude is related to the STE. According to the relationship between the amplitude and along-track velocity, the along-track velocity of target is estimated. Furthermore the across-track velocity of target is calculated. The 2D velocity of ground moving target can be accurately estimated in spectrogram with the proposed method. Finally, the feasibility and effectiveness of the proposed method are proved by the simulation results.

Key words: FMCW SAR, ground moving target, DPCA, spectrogram, slow time envelope

CLC Number: