调频连续波弹载SAR成像方法  

Imaging of missile-borne SAR based on FMCW

作　　者：周松[1] 周鹏[1] 张磊[1] 邢孟道[1] 保铮[1] 

机构地区：[1]西安电子科技大学雷达信号处理国家重点实验室,陕西西安710071

出　　处：《系统工程与电子技术》2011年第10期2203-2209,共7页Systems Engineering and Electronics

基　　金：国家自然科学基金(60890072)资助课题

摘　　要：调频连续波(frequency-modulated continuous-wave,FMCW)合成孔径雷达(synthetic apertureradar,SAR)具有体积小、重量轻、峰值功率低等优点,因此FMCW-SAR在精确制导领域具有较大的应用潜力。针对俯冲下降阶段的弹载SAR成像,建立了FMCW-SAR回波信号模型;通过分析可知,与常规机载FMCW-SAR不同,弹载条件下雷达平台相对较高的运动速度给差频输出信号引入特有的剩余二次相位,影响距离向的聚焦;针对该问题,提出了一种子孔径成像处理方法,通过在二维频域构造相应的剩余二次相位补偿函数,较好地改善了距离向的聚焦质量和成像效果。成像处理不涉及插值,所有操作均由快速傅里叶变换(fast Fourier trans-form,FFT)和相位点乘构成,运算效率较高。最后的点目标成像仿真实验验证了该方法的有效性。The combination of frequency-modulated continuous-wave （FMCW） technology and synthetic aperture radar （SAR） possesses several advantages, such as compact size, lightweight and less peak power, which provides great potential in the application of precision guidance. According to the downward movement for missile-borne SAR, a signal model of FMCW-SAR is proposed. To distinguish with traditional air-borne SAR, the effects of the residual quadratic phase term are introduced by the continuous motion under the condition of missile-borne peculiarly, which affect the focusing effect in the range direction. Due to the above rea- sons, an imaging method based on sub-aperture processing is presented. The residual quadratic phase term is compensated in the 2-D frequency domain, which improves the focusing quality and the imaging effect. Implemented by fast Fourier transform （FFT） and product without involving interpolation, the method is high in computational efficiency. Simulation results of point targets are provided to validate the effectiveness of the proposed method.

关 键 词：调频连续波 弹载合成孔径雷达 剩余二次相位 

分 类 号：TN959[电子电信—信号与信息处理]