基于重采样插值的菲涅耳望远镜成像算法研究

Imaging Algorithm of Fresnel Telescope Based on Resampling Interpolation

菲涅耳望远镜全孔径合成成像激光雷达(简称菲涅耳望远镜)是一种新的高分辨率激光成像技术。在菲涅耳望远镜一维扫描工作模式中,目标和扫描光束的相对运动使得时间-空间变换后的采样信号呈不规则非均匀分布,影响匹配滤波算法中快速傅里叶变换的使用。提出基于重采样插值的菲涅耳望远镜算法,包括时间-空间变换、重采样插值和匹配滤波等主要步骤,其中利用重采样插值将不规则分布的原采样信号转换为正交规则分布的重采样信号。对三种重采样插值方法进行比较,并获得了点目标和面目标的计算机仿真重建图像,证明了算法的有效性。该算法对于菲涅耳望远镜具有实际意义。

Fresnel telescope （short for Fresnel telescope full-aperture synthesized imaging lidar） is a new high resolution active laser imaging technique. In one-dimensional scanning operational mode of Fresnel telescope, spatial distribution of sampling signal is non-uniform because of the relative motion between target and scanning beam, which affects the fast Fourier transform in the following matched filtering algorithm. We propose the complete imaging algorithm for Fresnel telescopy, including space-time transform, resampling interpolation and matched filtering, in which we use resampling interpolation to transform the signal into two-dimensional uniform distribution form. Three different resampling interpolation methods are analyzed, and we get good reconstruction results of point target and area target with computer simulation, which prove that the designed imaging algorithm for Fresnel telescope is effective. This work has substantial practical value and offers significant benefit for Fresnel telescopy imaging system.