基于多普勒频率反投影的NCW-SAR动目标成像方法

传统合成孔径雷达(Synthetic aperture radar,SAR)成像依赖大带宽发射信号,研究证明SAR也可利用窄带连续波形(Narrowband continuous wave,NCW)具有的高多普勒分辨率实现场景的高分辨成像。NCW-SAR成像的优势在于占有很少的频带资源、降低系统成本和规模,更适用于通常带宽较窄的利用外辐射源波形的无源SAR。文中首先指出NCW-SAR的应用前景,简要回顾窄带动目标成像的发展,并分析NCW-SAR成像技术的现状。然后给出通用的SAR回波模型,提出NCW-SAR动目标成像方法,实现静止场景中动目标的聚焦,获得目标的速度估计,并分析速度分辨率。实验验证了NCW-SAR动目标成像方法的有效性。

Doppler Projection Based NCW-SAR Moving Target Imaging Method

Traditional synthetic aperture radar (SAR) imaging relies on wideband transformed waveforms. SAR using narrowband continuous waveforms (NCW) has been proved to be also able to achieve high resolution imaging exploiting high Doppler resolution. NCW-SAR has the following advantages: it occupies very small band resources, it promotes the development of low cost and small SAR, it is much applicable to passive SAR using illuminators of opportunity, which usually transmits waveforms with relatively narrow bandwidth. Firstly, the application potential of NCW SAR is pointed out. The development of narrowband imaging is briefly reviewed and the state of art NCW SAR imaging technology is analyzed. Then, a general SAR received signal model is presented and afterwards, a moving target imaging method for NCW SAR is proposed to focus the moving targets on the ground scene. The velocity estimation method as well as the velocity resolution analys is is also presented. The simulation results demonstrate the effectiveness of the proposed NCW SAR moving target imaging method.