航空学报 > 2019, Vol. 40 Issue (5): 322683-322683   doi: 10.7527/S1000-6893.2019.22683

基于虚拟慢时间的双基地ISAR成像算法

史林1, 韩宁2, 宋祥君2, 王立兵3, 崔东辉4   

  1. 1. 陆军工程大学石家庄校区 电子与光学工程系, 石家庄 050003;
    2. 中国人民解放军32181部队, 石家庄 050003;
    3. 中国人民解放军63961部队, 北京 100010;
    4. 中国人民解放军78616部队, 成都 610214
  • 收稿日期:2018-09-18 修回日期:2018-10-24 出版日期:2019-05-15 发布日期:2019-05-23
  • 通讯作者: 韩宁 E-mail:haning1103@163.com
  • 基金资助:
    国家自然科学基金(61601496)

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)

摘要: 针对双基地角时变引起的逆合孔径雷达(ISAR)图像畸变和散焦问题,提出了一种基于虚拟慢时间的成像算法。首先,分析了双基地角时变对ISAR成像的影响机理。然后,基于图像对比度最大准则估计等效旋转中心位置,完成初次相位补偿。最后,通过虚拟慢时间构建基于非均匀虚拟采样的补偿系数矩阵,并通过方位向非均匀傅里叶变换得到目标的ISAR像。算法基于图像对比度最大准则解决等效旋转中心位置估计问题,通过虚拟慢时间消除转动相位项的高次项影响,利用非均匀傅里叶变换解决随机虚拟采样的谱估计问题。理论分析和仿真结果验证了算法的有效性和鲁棒性。

关键词: 双基地逆合成孔径雷达, 时变双基地角, 畸变校正, 虚拟慢时间, 非均匀傅里叶变换

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

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