刘志声,王 乾,万 捷

摘 要:天线的中心频率、分辨率等因素是影响探地雷达脱空检测精度和准确度的主要因素,以此为出发点,在解释探地雷达脱空检测工作原理的基础上,对天线的中心频率、分辨率、采样率等各参数的计算方法和适用范围进行了全面分析和系统研究:根据道路材料介电特性及路面结构尺寸确定了天线中心频率的上限,参考脱空量值资料确定了天线中心频率的下限和最小垂直分辨率,按照优化处理要求结合经典理论规律提出了采样率计算公式,并将研究内容实践于清连一级路,吉林外环路,烟威高速路三项依托工程中,取得了良好的使用效果。

关键词:探地雷达;脱空检测;中心频率;分辨率;采样率

中图分类号:U141,TP274文献标识码:A

文章编号:1004-373X(2009)20-163-04

Parameter Research of Ground Penetrating Radar on Detecting Cavity

LIU Zhisheng1,WANG Qian2,WAN Jie2

(1.Xidian University,Xi′an,710071,China;2.Highway College,Chang′an University,Xi′an,710064,China)

Abstract:Both the central frequency of antenna and the resolution are chief factors influencing the accuracy of ground penetrating radar on detecting cavity.Considering it as the starting point,the methods of calculation and application for the parameters of central frequency of antenna,resolution and simpling frequency are analysed,and systematic research based on explaining the working principle of ground penetrating radar on detecting cavity.The upper limit of central frequency of antenna is recommended according to the dielectric property of road materials and the size of pavement structure.The low limit of central frequency of antenna and the minimal value of vertical resolution are determined by considering the data of cavity.The calculation formula of sampling frequency is presented according to the request of optimizing process with classical theory law.The contents are practised on attaching projects of Qingyuan-lianzhou highway,Jilin outer ring highway,Yantai-Weihai highway,achieving a good result.

Keywords:ground penetrating radar;detecting cavity;central frequency;resolution;sampling frequency

0 引 言

探地雷达是一种用于确定地下介质分布的广谱电磁技术。探地雷达脱空检测是一种高新技术检测,它实质上是一种高频电磁波发射与接收技术。在此通过直接向路基路面中发射射频电磁波,接收反射波而获得路基路面的采样信号,再经过硬件与软件处理,最后分析研究数据图像得到检测结果。探地雷达脱空检测具有探测效率高、无损性、高精度、抗干扰能力强、使用灵活方便等优点[1],在旧水泥混凝土路板底脱空检测中正得到越来越广泛的应用,发挥越来越重要的作用。

天线的中心频率、分辨率、采样率等因素是影响探地雷达脱空检测精度和准确度的主要因素,在此通过对这些因素进行全面分析和系统研究,推荐了各参数的计算方法和适用范围,并结合依托工程评价了使用效果,为今后探地雷达在道路工程中的应用提供了理论依据和技术支持。……