探地雷达电磁波正演模拟研究

利用探地雷达技术对路面结构层进行检测时,根据探测要求而采用不同频率的天线,尝试建立了雷达电磁波在结构层中传播的正演模型,通过得到的合成波模拟了其在结构层中传播的规律。根据经典电磁理论,利用傅立叶积分变换,通过典型激励和实测雷达入射波模拟了雷达电磁波在结构层中的传播情况,得到了合成的反射波,并与实际结构层测试雷达波做了比较。结果表明:频率低的情况下,雷达的分辨率较低,结构分层不明显;随着频率的增大,可以清晰区分出结构分层,但只有在高频率的条件下,结构厚度分层的反射信号才是合理的,能比较真实地反映实际情况。

Study on Forward Modeling of GPR Electromagnetic Wave Propagation

In order to using ground-penetrating radar technology to detect the road structures,antennas with different frequencies were introduced in accordance with the requirement of detection,the forward model which simulates electromagnetic wave propagates in the structures was established,and the propagation law was simulated through received composite wave signal.According to classic electromagnetic theory,propagation of radar waves in the layered structure was simulated based on typical excitation and real measured incident wave by using integral Fourier transform.The gained composite reflected wave was compared with the radar wave of the actual structure layer.The results show that(1)in the low frequency circumstances,the lower resolution radar results in obscurity in layered structure;(2)however,structure layer can be clearly distinguished,with increasing of frequency,and the reflected signal of the structure thickness layer is more reasonable and can reflect the actual situation only in the high-frequency condition.