1、摘要微波遥感作为重要的地球资源与环境信息获取手段，因其先进性而得到迅速发展。微波遥感机理研究如何从微波遥感数据源中提取有效的地物信息，具有十分重要的意义。介质材料的微波介电特性是微波遥感机理研究的主要内容，也是进行微波遥感电磁参数反演的基础。本论文从理论和实验两方面对介质介电常数测量方法进行了研究。论文首先对微波遥感的相关理论知识进行了介绍，并对介电常数常用测量方法进行了总结，讨论了实验室内的波导法和同轴探针法。其中波导法属于室内测量方法，通过料盒的引进能方便的测量样品介电常数，对于低损耗样品，这种测量方法精度很高；同轴探针法适合于高损耗介质测量，尤其适合于液体物质如水、盐水、油等介电常数的测
2、量。除了波导法、探针法，论文重点讨论了自由空间法。自由空间法属于实地测量方法的一种，它适合于测量大面积的目标的介电常数，并可以无损耗、非破坏的进行测量，更加适合于微波遥感实际应用。论文介绍了自由空间法的测量原理、定标以及介电常数的反演。为了方便野外实地测量以及微波遥感的实际需要，本文针对介电常数的测量，提出了一种实地测量介电常数的简易系统，给出了系统的测量原理。为后面的户外实地探测打好了基础。论文接下来对探地雷达进行了介绍，将探地雷达技术应用在路面检测方面，将前面的介电常数的测量理论知识与雷达技术结合起来。介绍了户外数据采集时的天线选择、参数选择及室内数据处理、资料解释等方面。基于微波遥感建立
3、了一套户外测试系统，通过探地雷达、天线、笔记本电脑对路面进行实地探测、采集数据、资料解释、数据处理及仿真成像，能够较为快速直观的的测量显示出路面厚度，将理论与实际有机的结合起来。数据处理方面，利用Reflex对采集到的数据进行：静校正（把地面定义为时间零点）、1维滤波（去直流飘移）、增益（能量衰减）、2维滤波 （背景去除）、1维滤波（巴特沃斯带通滤波）、2维滤波 （滑动平均），最终直观呈现路面侧切图以及厚度数据，能够做到准确、快速、高效。关键词：微波遥感，介电常数，波导法，自由空间法，探地雷达AbstractAbstract of dissertation should be concise
4、and clear, without comment and additional explanation. The content should include the purpose, method, result and conclusion, etc., it is independent and self-containedMicrowave remote sensing as an important means of acquiring information on the earths resources and environment has been rapidly dev
5、eloped due to its advanced nature. It is of great significance for microwave remote sensing mechanism research how to extract effective ground information from microwave remote sensing data sources. Microwave dielectric properties of dielectric materials are the main content of microwave remote sens
6、ing mechanism research, and also the basis for microwave remote sensing electromagnetic parameters inversion. This thesis studies the dielectric microwave and dielectric constant measurement methods from both theoretical and experimental aspects.Firstly, the paper introduces the relative theoretical
7、 knowledge of microwave remote sensing and summarizes the dielectric constant measurement methods. Besides, the waveguide method and the coaxial probe method in the laboratory are discussed. The waveguide method is an indoor measurement method. The dielectric constant of a sample can be conveniently
8、 measured through the introduction of a cartridge. For low-loss samples, this measurement method has high accuracy. The coaxial probe method is suitable for measuring high-loss media, and is particularly suitable for Measurement of the dielectric constant of liquid substances such as water, brine, a
9、nd oil.In addition to the waveguide method and probe method, the paper focuses on the free space method. The free space method is one of the field measurement methods. It is suitable for measuring the dielectric constant of a large-area target, and can perform measurement without loss and non-destru
10、ction, and is more suitable for practical applications of microwave remote sensing. The paper introduces the measurement principle, calibration and inversion of the permittivity of the free space method. In order to facilitate the field measurement and the actual needs of microwave remote sensing, t
11、his paper proposes a simple system for measuring the dielectric constant in the field of dielectric constant measurement, and gives the measurement principle of the system. It lays the foundation for the outdoor field detection. The paper then introduces the ground penetrating radar, applies the gro
12、und penetrating radar technology to the road surface inspection, and combines the previous theoretical knowledge of dielectric constant measurement with radar technology. The antenna selection, parameter selection, indoor data processing, and data interpretation during outdoor data acquisition are i
13、ntroduced. Based on microwave remote sensing, an outdoor test system was established. Ground penetrating radar, antenna, and notebook computer were used to conduct on-the-spot detection, data acquisition, data interpretation, data processing, and simulation imaging on the road surface. The road surf
14、ace thickness can be quickly and intuitively measured as combining theory and actual organic. For data processing, Reflex is used to perform static correction (defining the ground as time zero), 1D filtering (DC shifting), gain (energy attenuation), 2D filtering (background removal), and 1D filterin
15、g. (Butterworth Band pass Filtering) and 2D Filtering (Sliding Average) to visually present the road side cut and thickness data, which can be accurate, fast, and efficient.Key Words: Microwave remote sensing, Dielectric constant, Waveguide method, Free space method, Ground penetrating radar目录摘要IAbs
16、tractII目录IV第1章 绪论71.1 课题的研究背景及意义71.1.1 课题研究背景71.1.2 课题研究意义81.2 国内外发展现状91.3 研究内容111.4 论文结构12第2章 介电常数基本理论132.1 介电常数介绍132.1.1 介电常数的概念和作用132.1.2 介电常数与宏观电磁场的关系162.1.3 介电常数与微观物质特性及环境温度、压力的关系172.1.4 影响介电常数变化的因素182.2 地表粗糙度192.3 菲涅尔反射系数212.3.1 菲涅尔反射系数定义212.3.2 菲涅尔反射系数适用范围22第3章 介电常数测量系统设计243.1 波导法243.1.1 测量系统243.1.2 测量原理及计算243.1.3 存在的问题263.1.4 波导法改进设计273.1.5 软件部分333.3 自由空间法353.3