探地雷达(GPR)目前已经广泛应用于路面质量评价中,通过对GPR回波信号进行反演分析可以得到路面各层材料的厚度、介电常数等指标.构建探地雷达电磁波在路面结构层中传播的精确高效数值模型是保证反演精度和反演速度的关键.基于精细积分方法建立探地雷达电磁波在层状结构中传播的数值模型,该模型可精确模拟层状介质中探地雷达电磁波的传播过程.数值计算结果表明,模拟信号在波幅、时延等关键指标方面与实测波形吻合良好.此外,相比于传统时域有限差分方法,同等精度下,本算法可节省约40%的计算时间.
Ground Penetrating Radar( GPR) has been widely applied in pavement quality detection. Thickness and dielectric constant of pavement structure can be obtained by inverse analysis of GPR echo signal. The precise and efficient numerical model of electromagnetic wave propagation in layered pavement structure is a key for inversion. The precise integration method( PIM) is developed to simulate GPR wave propagating in layered structure in this paper. The numerical results show that simulated waveform fits well with measured signal,such as amplitude,time delay. In addition,the proposed method can save 40% CPU time compared with the traditional FDTD method.