基于线性调频步进信号的空间自旋目标时变三维成像方法

三维成像对空间目标测量、分类、识别等具有重要的意义。线性调频步进信号具有瞬时带宽较窄的特点,可获得较远的探测距离,在空间目标监视中具有优势。基于线性调频步进信号模型,提出了一种空间自旋目标时变三维成像的方法,并对由此产生的距离走动等问题进行了详细讨论。通过采用L型三天线雷达,首先分别获得各天线回波对应的高分辨距离像(high resolution range profile, HRRP)序列,然后利用Hough变换提取高分辨距离像序列中各个目标散射点的自旋运动特征,以获得各个散射点的自旋“轨迹”,最后通过对不同干涉平面内的高分辨距离像序列进行干涉处理,获得各散射点在每一慢时间时刻的空间方位向和俯仰向位置,结合高分辨距离像序列获得的距离向信息即可准确重构散射点的时变空间三维位置。仿真实验验证了文中自旋目标时变三维成像方法的有效性。

Time-varying three dimensional imaging for space rotating targets withstepped-frequency chirp signal

Three-dimensional (3-D) imaging is of great significance for space target measurement, cataloging and recognition. Stepped-frequency chirp signal (SFCS) owns narrow instantaneous bandwidth thus its detectable range is relatively large, which makes it ascendant in space surveillance. In this paper, based on SFCS, a time-varying 3-D imaging method for space rotating targets is proposed and some relevant problems are discussed in detail. In the method, with L-shaped three-antenna configuration, corresponding high resolution range profile (HRRP) series of each antenna are first obtained. Then through Hough transform, the curve parameter of each scatter in HRRP series is abstracted and the rotating trajectory is thus obtained. Finally, interferometric processing is conducted of HRRP series on different interferometric planes. The time-varying spatial positions in the azimuth and pitching directions of each target scatter are reconstructed. Combining with the time-varying positions in range direction extracted from HRRPseries, the time-varying 3-D image of target scatters is finally obtained. Simulation results verify the validity and robustness of the proposed method.