基于FMCW的弹载SAR俯冲成像方法研究

摘要

调频连续波合成孔径雷达具有体积小、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。针对俯冲运动状态下弹载FMCW SAR运动特点，提出了一种弹载FMCW SAR俯冲成像方法，在时域完成距离走动校正后，采用级数反演的方法推导了FMCW SAR回波信号精确方位多普勒频域表达式，通过对多普勒频域表达式的分析，构造相应的补偿函数完成目标的二维成像。最后点目标和场景目标仿真实验验证了理论分析与该成像方法的有效性。%The frequency modulated continuous wave (FMCW) synthetic aperture radar (SAR) has the properties of compact size, lightweight, low cost and low power dissipation and therefore provides great potential in the application of precision guidance. This paper proposes an imaging method for missile-borne FMCW SAR based on the movement characteristic of the missile-borne FMCW SAR with diving. The range walk is corrected in the time domain. Then the return signal expression in the Doppler frequency domain is deduced via the method of series reversion. Some penalty functions are constructed to obtain the 2-D imaging via analyzing the expression. Finally, the imaging simulations of point target and scene are given for validating the theoretical derivation and the effectiveness of the proposed imaging method.