探地雷达极化探测时域有限差分法模拟效果分析

采用不同天线极化方式进行探地雷达探测时得到的雷达图像是不同的,研究不同属性的目标体在不同极化方式下的雷达信号响应特征,可以指导工作人员在实际应用中对异常的解释。根据天线与测线的分布方向可分为xx,xy,yx,yy四种天线极化方式。本文基于电磁波的极化理论和天线的极化方式,利用时域有限差分法进行正演模拟,分析不同属性不同延伸方向目标体不同极化方式的探测效果。通过模拟分析,无论何种类型的目标体,采用xx和yy天线极化方式比用xy和yx方式得到的雷达信号强度大;对于不同延伸方向的目标体,xx极化方式的信号呈现一定的规律性。已知地下目标体走向和属性时,可采用适当的极化方式和测线来测量;当地下目标体未知时,可根据不同极化测量得到的信号特征来分析地下异常体的属性和走向。

The Simulation of GPR Polarization Exploration Response with Finite-Difference Time-Domain Method

The GPR detection with different polarization antenna modes has different image result.It＇s meaningful for our practical application to interpret the differences between GPR images.These mainly include xx,xy,yxand yypolarization mode.Based on the polarization theory in electromagnetic wave,this paper analyzes the antenna polarization and uses the Finite-Difference Time-Domain method to simulate the intensity of the electromagnetic field.According to the GPR polarization response on objects,this paper concludes that the radar signal received by the receiving antenna is controlled by the extension direction of transmitting and receiving antenna.The GPR signal which is received by the receiv-ing antenna in the mode of xxand yypolarization are stronger than that of xyand yxpolarization.The signal shows some regular principle.The appropriate method can be used to detect the underground targets when we have known the linear direction and property of the object,which can get a better radar detection result.In addition,we can also speculate the property and the direction of target by analyzing the profile received with different modes of polarization when the information of the target underground is unknown.