摘要
为了更好地解译探地雷达(ground-penetrating radar, GPR)回波数据,建立了一种二维时域有限差分模型,用于模拟地下分层结构(混凝土层/粘土层)和多个埋藏目标(金属板/条、空洞、水/油管)的GPR探测.对于该模型,地下分层结构中的分界面设置为粗糙界面,采用电磁微分高斯脉冲作为GPR源,并用单轴完全匹配层介质对计算区域边界进行截断以模拟无界区域.通过数值计算得到了探地雷达B-scan扫描的回波仿真结果,并讨论了埋藏深度、几何形状、介电常数、电导率等对回波散射特性的影响,以及目标受其上方不同粗糙度的粗糙界面影响而产生的回波形态的改变.该结果中显示的各个回波的形态、方位、振幅强弱以及到达的时间均与模型中各个结构的外形、位置、媒质特性及埋藏深度相一致,验证了该计算模型的有效性.
In order to better interpret the echo data of ground-penetrating radar (GPR), a two-dimensional finite difference time domain model is established to simulate the GPR detection of underground layered structure (concrete/clay layer) and multiple buried targets (metal plate or strip, hole, water or oil pipe). For the model, the interface in the underground layered structure is set to a rough interface, and the electromagnetic differential Gauss pulse is used as the GPR source. To simulate the unbounded scattered field existing in an infinite free space, the computing region is truncated by using the uniaxial perfectly matched layer medium. The simulation results of GPR B-scan echo are obtained by numerical calculation, the effects of target depth, geometry shape, permittivity and conductivity on the scattering characteristics are discussed, and the change of target echo shape produced by the influence of rough surface with [CM(46][JP2]different roughness on the target is analyzed. The results show that the shape, orientation, amplitude strength and arrival time of each echo are consistent with the shape, location, medium characteristics and buried depth of each structure in the model, which verifies the validity of the calculation model.
作者
刘颖
郭立新
LIU Ying;GUO Lixin(School of Physics and Optoelectronic Engineering, Xidian University, Xi’an, 710071, China;College of Electronic Engineering, Tianjin University of Technology and Education, Tianjin, 300222, China)
出处
《电波科学学报》
EI
CSCD
北大核心
2019年第1期111-118,共8页
Chinese Journal of Radio Science
基金
国家自然科学基金创新研究群体科学基金(61621005)
国家自然科学基金重点项目(61431010)
天津职业技术师范大学科研发展基金(KJ1818)
关键词
探地雷达(GPR)
粗糙界面
多个埋藏目标
回波特性
时域有限差分模型
ground-penetrating radar
rough interface
multiple buried targets
echo characteristics
finite difference time domain model
