基于传输线矩阵法的层状结构探地雷达正反演研究
发布时间：2018-12-10 14:55
【摘要】：探地雷达作为一个快速、高效、无破损的探测工具，已经广泛应用于道路工程无损检测中。通过对实测探地雷达信号进行反演分析，可以对路面结构层厚度、介电参数、含水量以及是否存在脱空等结构病害做出判断。进行反演分析的关键就是构建探地雷达电磁波在层状有耗介质中传播的正演模型和寻找高效的反演优化算法。本文针对目前探地雷达正反演算法中存在的一些问题，提出了基于传输线算法的正演模型以及基于1D-TLM剥层反演的反演策略，该方法对探地雷达基础理论与应用技术的发展具有一定推动作用。取得的主要成果和结论如下： （1）基于TLM方法建立了探地雷达电磁波在层状有耗介质中的传播模型。将FDTD算法中的PML边界条件引入到TLM方法中，依据该模型模拟合成了层状结构体中探地雷达的反射信号，通过与FDTD算法模拟结果进行对比，验证了算法模型的有效性和精确性。 （2）从反演问题的本质出发，将1D-TLM模型方法与剥层法相结合，建立了基于1D-TLM的模型参数调整算法。 （3）运用谱估计技术对仿真信号和探地雷达实际信号进行了处理，仿真和实验结果表明MUSIC方法得到的信号功率谱曲线可以准确的估计出信号中所含正弦波的个数及其频率，MUSIC与最小二乘法的结合算法能够估计出各信号的幅值分量和相位参数，达到对实际信号进行噪声处理的目的。 （4）将雷达信号预处理技术与基于TLM的正反演算法结合起来成功用于实际层状路面结构分析，实验结果表明本文算法可以用于实际层状结构处理，得到反演结果误差控制在了8%内，能够满足工程精度需要；利用探地雷达方法讨论了标准砂含水量与介电常数的关系，根据实际实验数据重新拟合了Topp公式和Alharathi公式，进一步验证了探地雷达方法检测层状结构层含水量的实用性。
[Abstract]:Ground penetrating radar (GPR), as a fast, efficient and nondestructive detection tool, has been widely used in road engineering nondestructive testing. Based on the inversion analysis of the measured ground penetrating radar signal, the structural diseases such as the thickness of pavement structure layer, dielectric parameters, water content and the existence of voids can be judged. The key of inversion analysis is to construct the forward model of ground penetrating radar electromagnetic wave propagation in layered lossy medium and to find an efficient inversion optimization algorithm. In this paper, aiming at some problems existing in GPR forward and inverse algorithms, the forward modeling based on transmission line algorithm and the inversion strategy based on 1D-TLM stripping inversion are proposed. This method can promote the development of the basic theory and application technology of GPR. The main results and conclusions are as follows: (1) based on TLM method, the propagation model of GPR electromagnetic wave in layered lossy media is established. The PML boundary condition in the FDTD algorithm is introduced into the TLM method, and the reflected signals of the ground penetrating radar in the layered structure are simulated and synthesized according to the model. The validity and accuracy of the model are verified by comparing the results with the simulation results of the FDTD algorithm. (2) starting from the essence of the inversion problem, a model parameter adjustment algorithm based on 1D-TLM is established by combining the 1D-TLM model method with the delamination method. (3) the simulated signal and the actual signal of ground penetrating radar are processed by using spectrum estimation technique. The simulation and experimental results show that the power spectrum curve obtained by MUSIC method can accurately estimate the number and frequency of sinusoidal wave contained in the signal. The combination of MUSIC and least square algorithm can estimate the amplitude components and phase parameters of each signal, and achieve the purpose of noise processing of the actual signal. (4) the radar signal preprocessing technology and the forward and inverse algorithm based on TLM are successfully applied to the analysis of the actual layered pavement structure. The experimental results show that the proposed algorithm can be used in the practical layered structure processing. The error of inversion results is controlled within 8%, which can meet the need of engineering precision. The relationship between the moisture content of standard sand and the dielectric constant is discussed by using the GPR method. The Topp formula and the Alharathi formula are refitted according to the actual experimental data, and the practicability of the GPR method in detecting the moisture content of the layered structure is further verified.
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P631.3;U412.22
本文编号：2370778
[Abstract]:Ground penetrating radar (GPR), as a fast, efficient and nondestructive detection tool, has been widely used in road engineering nondestructive testing. Based on the inversion analysis of the measured ground penetrating radar signal, the structural diseases such as the thickness of pavement structure layer, dielectric parameters, water content and the existence of voids can be judged. The key of inversion analysis is to construct the forward model of ground penetrating radar electromagnetic wave propagation in layered lossy medium and to find an efficient inversion optimization algorithm. In this paper, aiming at some problems existing in GPR forward and inverse algorithms, the forward modeling based on transmission line algorithm and the inversion strategy based on 1D-TLM stripping inversion are proposed. This method can promote the development of the basic theory and application technology of GPR. The main results and conclusions are as follows: (1) based on TLM method, the propagation model of GPR electromagnetic wave in layered lossy media is established. The PML boundary condition in the FDTD algorithm is introduced into the TLM method, and the reflected signals of the ground penetrating radar in the layered structure are simulated and synthesized according to the model. The validity and accuracy of the model are verified by comparing the results with the simulation results of the FDTD algorithm. (2) starting from the essence of the inversion problem, a model parameter adjustment algorithm based on 1D-TLM is established by combining the 1D-TLM model method with the delamination method. (3) the simulated signal and the actual signal of ground penetrating radar are processed by using spectrum estimation technique. The simulation and experimental results show that the power spectrum curve obtained by MUSIC method can accurately estimate the number and frequency of sinusoidal wave contained in the signal. The combination of MUSIC and least square algorithm can estimate the amplitude components and phase parameters of each signal, and achieve the purpose of noise processing of the actual signal. (4) the radar signal preprocessing technology and the forward and inverse algorithm based on TLM are successfully applied to the analysis of the actual layered pavement structure. The experimental results show that the proposed algorithm can be used in the practical layered structure processing. The error of inversion results is controlled within 8%, which can meet the need of engineering precision. The relationship between the moisture content of standard sand and the dielectric constant is discussed by using the GPR method. The Topp formula and the Alharathi formula are refitted according to the actual experimental data, and the practicability of the GPR method in detecting the moisture content of the layered structure is further verified.
【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P631.3;U412.22
【参考文献】
相关期刊论文 前10条
1 魏超;李小凡;郑晓东;;基于群体搜索的串行蒙特卡罗反演方法的并行算法(英文)[J];Applied Geophysics;2010年02期
2 刘四新;曾昭发;徐波;;三维频散介质中地质雷达信号的FDTD数值模拟[J];吉林大学学报(地球科学版);2006年01期
3 仝传雪;刘四新;王春辉;;时域有限差分法(FDTD)模拟探地雷达极化测量[J];吉林大学学报(地球科学版);2006年S1期
4 周辉林;田茂;熊俊志;;探地雷达回波信号的特征提取和分类[J];电波科学学报;2006年04期
5 王波;吴振森;赵振维;王红光;;基于蚁群算法的雷达海杂波反演蒸发波导研究[J];电波科学学报;2009年04期
6 邓世坤;克希霍夫积分偏移法在探地雷达图象处理中的应用[J];地球科学;1993年03期
7 冯德山;戴前伟;;高速公路路面厚度探地雷达检测[J];地球物理学进展;2008年01期
8 邓世坤,王惠濂;探地雷达图像的正演合成与偏移处理[J];地球物理学报;1993年04期
9 张云华，陈抗生;传输线矩阵方法的研究及其应用进展[J];电子学报;1995年06期
10 吴小利;;祁连山北缘断裂滑动参数的GPS数据蚁群算法反演研究[J];工程地球物理学报;2011年02期
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