微位移监测系统关键技术研究

发布时间：2018-01-10 06:15

本文关键词：微位移监测系统关键技术研究　出处：《电子科技大学》2016年硕士论文　论文类型：学位论文

【摘要】：微位移监测对山体滑坡等自然地质灾害或是大型建筑物的安全监测有着十分重要的意义。与传统测量方式相比,合成孔径雷达干涉测量技术(InSAR)具有低成本、高精度、全天候实时远程连续监测的独特优势。对于局部区域的形变监测,地基D-InSAR技术具有广泛的应用前景。本文的主要工作围绕地基D-InSAR中使用的合成孔径技术、差分干涉测量技术与宽带线性调频连续波三大关键技术展开,重点对地基D-InSAR进行了系统设计和仿真验证。首先围绕局部目标区域微位移特点,研究建立了地基D-InSAR监测系统观测模型,推导了地基D-InSAR测量形变流程,详细分析了影响测量的因素,包括相干源与真值解算误差。然后针对如何提高地基D-InSAR系统距离分辨率,研究了宽带线性调频连续波(LFMCW)技术。并针对采用宽带LFMCW体制的地基D-InSAR系统,研究推导了将发射信号作为参考信号的改进频率变标(FS)成像算法。接着针对微位移检测方法,为了提高系统的测量精度,本文对地基D-InSAR监测系统的干涉条纹、图像配准、图像噪声及滤波方法进行了研究。其中,重点研究了相位解缠绕算法,从运行时间与精度两个面对枝切法、质量引导法与等权最小二乘法进行仿真比较,选择枝切法作为本文地基D-InSAR系统的主要解缠绕方法。最后本文根据理论研究成果,设计了一套基于宽带LFMCW的地基D-InSAR监测系统,其监测范围为100m到4000m,采用了调频带宽500MHz、载频10GHz的线性调频连续波。该设计中,信号处理板利用单片AD9240进行5MHz的高精度采样,利用单片Xilinx-XC7VX690T-FPGA进行高速成像。本文给出了板卡功能框图及信号处理流程,并利用MATLAB平台对参数设计与系统设计进行了仿真验证,证明了测量精度可达1mm。系统拥有精度高、功耗低、成本低与可实现性高等特点。
[Abstract]:Micro-displacement monitoring is of great significance to the safety monitoring of natural geological hazards such as landslides or large buildings. Synthetic Aperture Radar Interferometry (InSAR) has the unique advantages of low cost, high precision, real-time remote continuous monitoring around the clock, and can be used to monitor deformation in local areas. The ground-based D-InSAR technology has a wide application prospect. The main work of this paper focuses on the synthetic aperture technology used in ground-based D-InSAR. Differential interferometry and wideband LFM continuous wave are the three key technologies. The system design and simulation of ground-based D-InSAR are emphasized. Firstly, the characteristics of micro-displacement in local target region are discussed. The observation model of ground-based D-InSAR monitoring system is established, the deformation flow of ground D-InSAR measurement is deduced, and the factors affecting the measurement are analyzed in detail. The error between coherent source and true value is included. Then, how to improve the range resolution of ground-based D-InSAR system is discussed. The broadband LFM continuous wave (LFMCW) technology is studied, and the ground-based D-InSAR system using wideband LFMCW system is studied. The improved FS-based imaging algorithm which takes the transmitted signal as the reference signal is studied and deduced. Then, aiming at the micro-displacement detection method, the measurement accuracy of the system is improved. In this paper, interference fringes, image registration, image noise and filtering methods of ground-based D-InSAR monitoring system are studied. The operation time and accuracy of the two face branch cutting method, quality guidance method and equal weight least square method were simulated and compared. The branch tangent method is chosen as the main unwinding method of the ground-based D-InSAR system. Finally, according to the theoretical research results. A ground-based D-InSAR monitoring system based on wideband LFMCW is designed. Its monitoring range is 100m to 4000m, and the frequency modulation bandwidth is 500MHz. In this design, the signal processing board uses a single chip AD9240 to carry out high precision sampling at 5MHz. In this paper, the function block diagram of the board and the signal processing flow are given. The simulation of parameter design and system design based on MATLAB platform proves that the measurement precision can reach 1 mm. the system has the characteristics of high precision, low power consumption, low cost and high realizability.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH822;TP274

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