计算机应用 ›› 2011, Vol. 31 ›› Issue (10): 2734-2737.DOI: 10.3724/SP.J.1087.2011.02734

• 图形图像技术 • 上一篇    下一篇

双参数估计的改进自聚焦算法

唐波1,2   

  1. 1.中国科学院电子学研究所 微波成像技术国家重点实验室,北京 100190
    2.中国科学院研究生院,北京 100049
  • 收稿日期:2011-04-20 修回日期:2011-06-20 发布日期:2011-10-11 出版日期:2011-10-01
  • 通讯作者: 唐波
  • 作者简介:唐波(1985-),男,广西桂林人,硕士研究生,主要研究方向:高分辨率机载SAR、实时成像处理。
  • 基金资助:

    国家863计划项目(2007AA120303)

Improved auto-focus algorithm of dual parameters estimation

TANG Bo1,2   

  1. 1.National Key Laboratory of Microwave Imaging Technology, Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China
    2.Graduate University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2011-04-20 Revised:2011-06-20 Online:2011-10-11 Published:2011-10-01
  • Contact: Tang Bo

摘要: 传统自聚焦算法的多普勒调频率拟合模型中当最近斜距存在误差时,由于只考虑载机地速对多普勒调频率的影响,导致多普勒调频率拟合后会引入沿距离向变化的二次相位误差,该二次相位误差会严重影响高分辨率合成孔径雷达(SAR)成像的质量。为解决此问题,通过分析载机地速和最近斜距两个系统参数存在误差时对多频率调频率拟合的影响,提出了基于自聚焦算法结合最小二乘方法联合估计最近斜距和载机地速的双参数估计算法。该算法采用的估计模型相比于传统单参数估计算法更加符合真实的方位多普勒模型,在没有外定标的情况下可以很好地估计最近斜距误差。最后通过实测数据成像验证了该算法在高分辨率SAR成像中的有效性和适用性。

关键词: 自聚焦, 多普勒调频率, 双参数估计, 最小二乘

Abstract: To figure out the phase error in the high-resolution Synthetic Aperture Radar (SAR) imaging caused by using traditional auto-focus algorithm in which only velocity is considered, the quality of SAR image was analyzed when errors of two parameters of Doppler rate exist. One method of estimating both velocity and the nearest distance of range was proposed, which was based on the mathematic model that was much closer to the real, and this method could estimate the nearest range better. Finally, the testing data verify the effectiveness and applicability of the algorithm in the high-resolution SAR imaging.

Key words: auto-focus, Doppler rate, dual parameters estimation, least square

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