基于先验信息补偿的太赫兹雷达近场大转角精细成像研究

基于雷达成像技术实现太赫兹频段目标散射特性获取是一种重要的特性测量手段，其前提是能够获得目标的高分辨精细成像结果。针对室内太赫兹雷达系统成像测量时难以保证参考目标中心和转台中心完全重合，且近场成像结果敏感于目标位置误差的实际问题，推导建立了相应的精确成像模型，提出了基于先验信息的距离误差补偿方法和近场成像算法实现方法，得到了近场大转角条件下太赫兹目标高分辨精细成像结果。经实验系统测量验证，该成像方法可精确修正目标位置摆放误差和近场测量误差造成的图像形变与散焦，无目标坐标系和雷达坐标系中心重合的要求限制，为太赫兹频段目标散射特征精确反演和散射中心诊断提供了重要支撑。

Research on Terahertz Radar Near-Field Imaging with Large Rotation Angle Based on Prior Information Compensation

Terahertz scattering characteristic acquisition of targets by radar imaging is an important way of scattering measurement, and its premise is to obtain the high resolution and fine imaging results.Aimed at the problems that measurement of imaging in terahertz radar system is difficult to guarantee a complete consistency between the target center and the turntable center during measurement,and the results of imaging are sensitive to position error of targets for the near field terahertz radar system, in this paper, a corresponding accurate imaging model is deduced and established, a method of distance error compensation based on prior information is presented, and a realization of imaging algorithm is proposed, achieving the target’s high resolution fine image acquisition under condition of near field and large rotation angle. The experimental results show that the proposed imaging method can accurately correct the image distortion and defocus caused by the positioning error and near-field factors of the target, and is not subject to the coincidence of the center of the target coordinate system and the radar coordinate system. The study could pave the way for image-based target scattering feature extraction and scattering center diagnosis in terahertz band.