阵列式探地雷达信号极化场特征

Characteristics of the Signal Polarization Field in Array Type Ground Penetrating Radar

阵列式观测是探地雷达系统研制和新型探测方法的一个重要发展趋势,而同形多源并发地下目标响应特征分析成为系统研制和数据处理研究的基础和前提。阵列式天线的多源并发信号及目标反射信号存在复杂的极化特性,但同时也包含更多目标特征的响应信息。本文针对基于似平面波探地雷达系统,分析了目标体在极化平面波照射下的响应特征,从多极化信号角度分析典型地下目标体形态特征;并采用时域有限差分正演分析方法,通过对阵列天线接收到的数据沿时间轴进行积分来获得目标在地表投影的分布情况,分析了一维及二维分布的收发天线阵列对目标的检测。研究成果表明,多极化综合特征分析能够有效改善目标检测的稳定性,提高目标响应信号的信噪比,减弱天线方向图和目标散射截面闪烁对数据剖面的影响,降低数据处理和解释的难度。

With the trend of the detection method using array observation,the GPR（ground penetrating radar）system takes the response characteristic analysis for the isomorphic multisource concurrent underground target as the basis and precondition for the system development and data processing.The multisource concurrent signal and target echo signal of the array antenna withcomplicated polarization characteristics,contain more response message about the target characteristics.Aiming at the plane wave like MIMO（multiple-input multiple-output）GPR system,this paper analyzes the response characteristics of the target in polarization plane wave illumination and the morphological characteristics of the model underground target through its multi-polarization signal.The surface projection distribution of the target is acquired through the integration along time axis of the data received by the array antenna,and the targets of the transmit-receive array antenna in 1-D and 2-D distribution are detected and analyzed by the time domain finite-difference forward modeling method.The research results that multi-polarization integrated characteristic analysis can improve effectively the consistency of the target detection,promote the signal to noise ratio（SNR）of the target response signal,abate the influence from the antenna pattern and target scattering cross-section blink upon the data section,and decrease the difficulty in data processing and interpretation.