系统工程与电子技术

• 传感器与信号处理 • 上一篇    下一篇

基于改进NCS算法的弹载FMCW SAR大斜视成像方法

梁颖1,2, 张群1, 杨秋1, 顾福飞1, 何彦杰2   

  1. (1. 空军工程大学信息与导航学院, 陕西 西安 710077;
    2. 中国人民解放军95980部队, 湖北 襄阳 441100)
  • 出版日期:2016-07-22 发布日期:2010-01-03

#br# Study on the high squint imaging method for missileborne#br# FMCW SAR based on extended NCS algorithm

LIANG Ying1,2, ZHANG Qun1, YANG Qiu1, GU Fu-fei1, He yan-jie2   

  1. (1. Institute of Information and Navigation, Air Force Engineering University, Xi’an 710077, China)
    (2. Unit 95980 of PLA, Xiangyang 441100, China)
  • Online:2016-07-22 Published:2010-01-03

摘要:

调频连续波(frequency modulated continuous wave,FMCW)合成孔径雷达(synthetic aperture radar,SAR)具有体积小、重量轻、成本低、功耗低等优点,在精确制导领域具有较大的应用潜力。推导分析了弹载FMCW SAR大斜视回波信号波数域表达式,在成像预处理中,通过引入全时间距离走动校正函数,有效避免了由导弹高速运动及大斜视角观测引起的二次相位误差的产生;在方位向处理中,给出了一种改进的非线性调频变标算法(nonlinear chirp scaling,NCS),补偿了方位空变相位误差,实现了方位向的高精度成像。最后仿真实验验证了理论分析结果及所提成像方法的有效性。

Abstract:

The frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR) has the properties of compact size, lightweight, low cost and low power dissipation, which provides great potential in the application of precision guidance. The return signal expression in the wave number domain is deduced and analysed. In the imaging preprocessing, the quadratic phase error which is induced by the high speed and high squint angle is not generated, according to the inducing of the alltime range walk correction function. In the azimuth processing, an extended nonlinear chirp scaling algorithm is proposed. The azimuthvariance phase error is compensated, and a high precise azimuth imaging is achieved. Finally, some results are given for validating the theoretical derivation and the effectiveness of the proposed method.