超宽带穿墙雷达椭圆包络线目标边界成像算法

Target Shape Imaging Algorithm with an Envelope of Ellipses for UWB-TW Pulse Radars

为解决传统超宽带穿墙雷达后向投影(BP)成像算法不利于实时成像且成像模糊的问题,基于目标边界成像的成像算法成为近年来研究的热点。SEABED算法与Envelope算法是常用的目标边界成像算法,但此类算法存在抗噪性差或准确性不佳等不足。该文采用收发分置天线方式,提出一种基于椭圆包络线原理的成像算法。通过分析目标边界与天线坐标之间的几何结构,构造与目标边界相切的椭圆模型,推导了两者的映射关系,完成了穿墙成像的目标边界重建。理论分析和实验结果表明,该算法能提高成像的抗噪性与准确性,增强了穿墙成像的性能。

The target shape imaging algorithms receive great attention in applications of Ultra WideBand Through Wall （UWB-TW） radar, because it overcomes the shortcomings of real-time imaging and image quality in traditional Back Projection （BP） imaging algorithms. The classical SEABED and Envelope algorithms are typical target shape imaging algorithms, which have still some defects such as poor anti-noise capability and imaging accuracy. This paper presents a target shape imaging algorithm with the envelope of ellipses for the bistatic UWB-TW radar. The ellipse model regarding a target boundary is established by analyzing the geometry relationship between the target boundary and the coordinates of antennas. With this model, the target boundary can be expressed as a boundary of a union and an intersection set of these ellipses to achieve the target shape imaging, which derives from their mapping relationship. The results of numerical simulations and experiments show that the proposed algorithm can improve the imaging accuracy and the capability of anti-noise, leading to the better performance of through-wall imaging.