航空学报 > 2015, Vol. 36 Issue (2): 605-613   doi: 10.7527/S1000-6893.2014.0272

基于两维空变滤波的PFA波前弯曲误差补偿

丁岚1,2, 毛新华1,2, 朱岱寅1,2   

  1. 1. 南京航空航天大学 雷达成像与微波光子技术教育部重点实验室, 南京 210016;
    2. 南京航空航天大学 电子信息工程学院, 南京 210016
  • 收稿日期:2014-02-24 修回日期:2014-09-28 出版日期:2015-02-15 发布日期:2014-10-10
  • 通讯作者: 毛新华 Tel.: 025-84896490 E-mail: xinhua@nuaa.edu.cn E-mail:xinhua@nuaa.edu.cn
  • 作者简介:丁岚 女,博士研究生。主要研究方向:合成孔径雷达信号处理。Tel:025-84892452 E-mail:dingl@nuaa.edu.cn;毛新华 男,博士,副教授,硕士生导师。主要研究方向:雷达成像/压缩感知成像。Tel:025-84896490 E-mail:xinhua@nuaa.edu.cn
  • 基金资助:

    国家自然科学基金(61301210);江苏省自然科学基金(BK20130815);教育部博士点基金(20123218120021)

Polar format algorithm wavefront curvature error compensation using 2D space-variant post-filtering

DING Lan1,2, MAO Xinhua1,2, ZHU Daiyin1,2   

  1. 1. Key Laboratory of Radar Imaging and Microwave Photonics, Ministry of Education, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China;
    2. College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
  • Received:2014-02-24 Revised:2014-09-28 Online:2015-02-15 Published:2014-10-10
  • Supported by:

    National Natural Science Foundation of China (61301210); Natural Science Foundation of Jiangsu Province (BK20130815); Ph. D. Programs Foundation of Ministry of Education of China (20123218120021)

摘要:

极坐标格式算法(PFA)因受波前弯曲误差的影响,其有效成像场景范围受到一定的限制。采用图像域的空变滤波(SVPF)处理可以有效补偿波前弯曲误差,但为了简化分析,已有SVPF方法在补偿过程中都采取了一定的近似,在对大场景进行高分辨率成像时仍然不能满足聚焦精度要求。对PFA的极坐标格式转换给出了一种新的解析解释,利用该解释推导得到了精确的波前弯曲误差表达式;基于该波前弯曲误差模型,提出了一种基于两维SVPF处理的波前弯曲误差补偿方法。最后通过仿真数据处理验证了该算法的有效性。

关键词: 合成孔径雷达, 极坐标格式算法, 波前弯曲误差补偿, 空变滤波, 两维滤波

Abstract:

The space-variant defocus effect introduced by wavefront curvature error in polar format algorithm (PFA) imagery limits its maximal focused scene size. Space-variant post-filtering (SVPF) is an efficient approach to compensate for this error. However, to simplify the analysis, all the existing SVPF methods take some approximation on the wavefront curvature error. They can still not meet the required precision when imaging large area with very high resolution. In this paper, we provide a new analytical interpretation of polar format algorithm and develop the accurate wavefront curvature expression in 2D spatial frequency domain. Base on this accurate expression, a 2D SVPF is proposed to accurately correct the wavefront curvature error. Finally, simulation experiment validates the theoretical analysis.

Key words: synthetic aperture radar, polar format algorithm, wavefront curvature error compensation, space-variant post-filtering, two-dimensional filter

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