FMCW地基SAR系统设计与互耦抑制技术研究

发布时间：2018-05-09 00:29

本文选题：FMCW + SAR　；参考：《北京理工大学》2016年硕士论文

【摘要】：调频连续波雷达系统具有结构简单、峰值功率低、无盲区和高分辨等特点,适合用于大范围边坡地表监测的地基SAR监测系统。本文对高分辨FMCW地基SAR系统设计方法与连续波雷达耦合信号的分析与抑制方法进行了研究,主要包括以下几个方面的内容:1.针对地基SAR系统的特点和低功耗、小体积的设计约束要求,开展高分辨地基SAR系统设计方法研究。通过分析雷达系统性能需求和实现复杂度,确定了雷达体制、雷达频段和信号波形,并根据雷达辐射场景需求设计雷达的发射功率。同时得到了全系统相参性下,微波本振、数字频率和触发信号的约束条件。根据SAR系统成像指标的设计要求,提出了一种适用于FMCW地基SAR的系统隔离度指标的分析方法。2.针对FMCW SAR系统的特点,分析雷达系统耦合信号的来源、传递路径和信号畸变特性,建立了雷达系统耦合信号模型,并分析了耦合信号对地基SAR系统辐射区域成像的影响。根据高速示波器采集的雷达射频数据进一步分析了信号传递过程中相位畸变的组成。通过仿真和雷达实测数据验证了耦合信号对一维距离像和二维SAR成像影响的分析结果。3.针对耦合信号对地基SAR系统成像的影响,研究耦合信号数字对消方法。首先利用传统数字对消方法对耦合信号进行对消抑制处理。其次,针对传统方法无法实时更新对消参考信号的不足,提出一种基于奇异值分解(SVD Singular Value Decomposition)估计对消参考信号的耦合对消方法。采用回波数据矩阵划分,子矩阵分解来估计对消参考信号的方法,用于解决SVD对系统时间和空间开销大问题。通过开展外场雷达实验验证了该对消抑制方法的有效性。
[Abstract]:Frequency modulated continuous wave radar system has the advantages of simple structure, low peak power, no blind area and high resolution. It is suitable for ground SAR monitoring system for large scale slope surface monitoring. In this paper, the design method of high resolution FMCW ground SAR system and the analysis and suppression method of continuous wave radar coupling signal are studied, including the following aspects: 1. According to the characteristics of foundation SAR system and the design constraints of low power consumption and small volume, the design method of high resolution foundation SAR system is studied. By analyzing the performance requirements and the implementation complexity of radar system, the radar system, radar frequency band and signal waveform are determined, and the transmitting power of radar is designed according to the requirement of radar radiation scene. At the same time, the constraints of microwave local oscillator, digital frequency and trigger signal are obtained. According to the design requirements of SAR system imaging index, an analytical method of system isolation index for FMCW foundation SAR is proposed. According to the characteristics of FMCW SAR system, the source, transmission path and signal distortion characteristics of radar system coupling signal are analyzed. The coupled signal model of radar system is established, and the influence of coupling signal on the radiation region imaging of ground-based SAR system is analyzed. According to the radar RF data collected by high speed oscilloscope, the phase distortion in the signal transmission process is further analyzed. The effect of coupled signal on one-dimensional range profile and two-dimensional SAR imaging is verified by simulation and radar data. In view of the effect of coupled signal on the imaging of ground SAR system, the digital cancellation method of coupled signal is studied. Firstly, the traditional digital cancellation method is used to suppress the coupled signal. Secondly, a coupled cancellation method based on singular value decomposition (SVD Singular Value decomposition) is proposed to estimate the cancelling reference signal, which can not be updated in real time by the traditional method. The echo data matrix partition and submatrix decomposition are used to estimate the canceling reference signal, which is used to solve the problem of large time and space cost of SVD. The effectiveness of the cancellation and suppression method is verified by outfield radar experiments.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN957.51

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