导航

ACTA AERONAUTICAET ASTRONAUTICA SINICA ›› 2019, Vol. 40 ›› Issue (5): 322683-322683.doi: 10.7527/S1000-6893.2019.22683

• Electronics and Electrical Engineering and Control • Previous Articles     Next Articles

Bistatic ISAR imaging algorithm based on virtual slow time

SHI Lin1, HAN Ning2, SONG Xiangjun2, WANG Libing3, CUI Donghui4   

  1. 1. Department of Electronic and Optical Engineering, Army Engineering University Shijiazhuang Campus, Shijiazhuang 050003, China;
    2. China PLA 32181 Unit, Shijiazhuang 050003, China;
    3. China PLA 63961 Unit, Beijing 100010, China;
    4. China PLA 78616 Unit, Chengdu 610214, China
  • Received:2018-09-18 Revised:2018-10-24 Online:2019-05-15 Published:2019-05-23
  • Supported by:
    National Natural Science Foundation of China (61601496)

Abstract: The distortion and defocusing of bistatic Inverse Synthetic Aperture Radar (ISAR) image are induced by the time-varying bistatic angle. To solve this issue, an imaging algorithm based on virtual slow time is proposed. First, the influence mechanism of time-varying bistatic angle on ISAR imaging is analyzed. Then, the equivalent rotation center position is estimated based on the maximum image contrast criterion, completing the initial phase compensation. Finally, the compensation coefficient matrix with non-uniform virtual sampling is constructed based on virtual slow time. The ISAR two-dimensional image of the target is obtained by non-uniform Fourier transform along Doppler direction. Based on the maximum image contrast criterion, the algorithm successfully estimates the equivalent rotation center position. The influence of the quadratic phase terms is alleviated via virtual slow time, and the spectrum estimation problem of random virtual sampling is solved by non-uniform Fourier transform. Theoretical analysis and simulation results have verified the effectiveness and robustness of the algorithm.

Key words: bistatic ISAR, time-varying bistatic angle, distortion mitigation, virtual slow time, non-uniform Fourier transformation

CLC Number: