复杂环境小管线FDTD正演模拟图像特征分析  

Image characteristic analysis of FDTD forward simulation of small pipeline in complex environment

作　　者：胡荣明[1] 滕坤阳 周自翔 杜嵩 姚燕子 李少杰 HU Rongming;TENG Kunyang;ZHOU Zixiang;DU Song;YAO Yanzi;LI Shaojie(College of Geomatics,Xi’an University of Science and Technology,Xi’an 710054,China;Investigation Bureau of Surveying and Mapping of Xi’an,Xi’an 710054,China)

机构地区：[1]西安科技大学测绘科学与技术学院,西安710054 [2]西安市勘察测绘院,西安710054

出　　处：《中国科技论文》2021年第5期529-535,共7页China Sciencepaper

基　　金：国家自然科学基金资助项目(41771576)。

摘　　要：为提高小管径管线(50~150 mm)在复杂地下环境中雷达图像回波剖面特征的解译精度和确定小管径管线的位置信息,利用时间域有限差分法模拟不同环境下PVC管、铜芯通信电缆、金属钢管这3种常见小管线,根据正演结果分析雷达回波响应特征。模拟结果显示:500 MHz天线中心频率下埋深1.4 m小管线的水平分辨率为41 cm,具有良好的信噪比,垂直分辨率为6.1 cm,受层状介质反射回波干扰,难以区分;不同的管线材质及承载物质,其雷达回波图像特征不同,承载物质对PVC管成像特征影响大,但对金属管线无影响;大管径管线和地下干扰体叠加形成的虚假回波,影响到周围的小管线判别;凹形层状介质形成了不规则反射面,在回波图像中产生了2个交叉抛物线异常回波特征标识,并且伴有杂乱多次波出现,干扰其上方管线回波成像。模拟结果有助于实际小管线探测识别。In order to improve the interpretation accuracy of the echo profile characteristics of radar images of small-diameter pipelines(50-150 mm)in complex underground environments,the location information of small-diameter pipelines was determined.The time domain finite difference method was used to simulate three common small pipelines in different environments,such as PVC pipes,copper core communication cables,and metal steel pipes,and the radar echo response characteristics were analyzed according to the forward modeling results.The simulation results show that the horizontal resolution of the small pipeline with a depth of 1.4 m at the center frequency of the 500 MHz antenna is 41 cm,a good signal-to-noise ratio,and a vertical resolution of 6.1 cm.It is difficult to distinguish due to the interference of the layered medium reflection echo;different pipeline materials and the carrier material,the radar echo image characteristics are different,the carrier material has a great influence on the imaging characteristics of the PVC pipe,but has no effect on the metal pipeline;the false echo formed by the superposition of the large-diameter pipeline and the underground interfering body affects the surrounding small pipeline discrimination;the concave layered medium forms an irregular reflection surface,and generates two cross-parabolic abnormal echo signatures in the echo image,and is accompanied by the appearance of cluttered multiple waves,which interferes with the echo imaging of the pipeline above it.The simulation result is helpful for the actual small pipeline detection and identification.

关 键 词：探地雷达 正演数值模拟 雷达图像特征 GprMax3.0软件 小管线探测 

分 类 号：TP75[自动化与计算机技术—检测技术与自动化装置]