摘要调频连续波合成孔径雷达(SAR)结合调频连续波技术和SAR技术各自的优点,可装载于轻型无人机,能够适应新型战争模式下的作战任务需要,受到很多国家和科研机构的关注。
由于在脉冲重复时间(Pulse Repetition Time,PRT)期间内的发射信号模式的差异,使得传统SAR信号处理的“停-走-停”近似不能直接应用在调频连续波SAR的信号处理,本文从调频连续波SAR信号特点出发,建立调频连续波SAR回波信号模型,在回波仿真方面重点讨论了时域直接叠加算法和基于傅氏变换的快速回波模拟算法。65544
从解调频(dechirp)角度出发,针对调频连续波SAR信号特点,和传统脉冲SAR比较,分析了由于传感器的连续运动所引起的脉内距离走动量,并给出相应补偿校正方式,利用BP、RD算法进行成像处理,并分析各项成像指标,验证所编写算法的有效性。最后利用美国的Brigham Young大学的实测飞行数据进行成像处理。
毕业论文关键词 调频连续波SAR 回波仿真 dechirp BP RD 成像处理 实测数据
毕业设计说明书(论文)外文摘要
Title Research of Frequency Modulated Continuous Wave
SAR Signal Processing
Abstract
Frequency Modulated Continuous Wave Synthetic Aperture Radar(FMCW SAR) system ,which combines the advantage of both the advanced technique of frequency modulated continuous wave and traditional SAR system, can be loaded in Mini Unmanned Aviation Vehicle (MUAV) .More and more attention is focused on it by many countries and institutions for its satisfaction relevant to the demand of campaign mission under new warfare modern.
Due to the difference in transmit signal mode during the pulse repetition time (PRT), approximations of “stop-go-stop” made in the traditional SAR signal processing can’t be directly applied in FMCW SAR signal processing. Based on the characteristic of the FMCW SAR signal, the dissertation establishes the echo mode of FMCW SAR, subsequently , the echo simulation is implemented by using algorithms with respect to the direct splice in time domain and Fourier transform ,respectively.
Moreover, based on the dechirp technique and the FMCW SAR signal characteristic, this thesis analyses the range migration during the PRT caused by continuous motion and processes a novel compensation algorithm. At last , the simulated data and the real data of American Brigham Young University are processed by using the BP and RD algorithms and the validity of the new technique is confirmed by evaluating the imaging performance with relevant index.
Keywords FMCW SAR; echo simulation; dechirp; BP;RD; image; raw flight mapping data
目录
1.绪论 1
1.1调频连续波SAR研究的背景和意义 1
1.3 论文的主要研究工作 4
1.4 论文结构安排 5
2.线性调频信号及脉冲压缩技术 6
2.1概述 6
2.2 线性调频信号 6
2.2.1 线性调频信号的时域分析 6
2.2.2线性调频信号的频域分析 7
2.3 脉冲压缩技术 10
2.3.1 脉冲压缩技术原理 10
2.3.2线性调频信号的脉冲压缩 11