基于ROSAR的高分辨波数域成像算法

Research on high resolution wavenumber-domain imaging algorithm for ROSAR

旋转式合成孔径雷达(rotor synthetic aperture radar,ROSAR)是一种新型成像雷达,在高分辨条件下,距离徙动对ROSAR成像结果影响严重。波数域成像算法利用插值操作实现距离徙动的精确校正,但由于ROSAR复杂的斜距历程,导致传统波数处理获得的二维波数谱形式复杂,难以进行插值操作。针对这一问题,提出了一种改进ROSAR波数域成像算法。重新构建角度维波数,通过求解隐函数获得易于插值操作的信号二维波数域表达式,设计参考函数消除高频调制影响,最终通过Stolt插值实现宽波束大场景下距离徙动无近似校正与精确聚焦。仿真实验验证了算法的可行性与有效性。

Rotor synthetic aperture radar （ROSAR） is a new mode of imaging radar. Under the condition of high resolution, range cell migration （RCM） has significant effects on the image. The wavenumber-domain imaging algorithm involves precise RCM correction by means of interpolation, but it is hard to use interpolation for two-dimensional wavenumber spectrum acquired by the traditional wavenumber-domain method, due to the complex expression of distance history. To deal with this problem, a modified wavenumber-domain imaging algorithm for ROSAR is proposed. The wavenumber vector is rebuilt in azimuthal angle domain, the 2-D wavenumber spectrum which is proper to perform interpolation can be obtained by solving implicit function, the reference function is designed to eliminate effects from high frequency modulation, the well-focused image and RCM correction with no approximation for wide-beam and large-scale scene are obtained by Stolt interpolation. The simulation results validate the effectiveness and feasibility of the proposed algorithm.