基于空时频联合处理的SAR运动目标检测

发布时间：2018-03-16 12:26

本文选题：合成孔径雷达　切入点：地面运动目标检测　出处：《国防科学技术大学》2014年硕士论文　论文类型：学位论文

【摘要】：多通道SAR-GMTI技术可以实现运动目标检测和高分辨雷达成像,具有重要的军用和民用价值,是当前SAR系统理论与应用研究的热点之一。本文对多通道SAR与时频分析理论相结合实现运动目标检测和参数估计问题作了比较深入的研究,所做的研究工作和取得的成果如下:(1)从静止目标回波模型出发,构建了运动目标回波模型,深入分析了目标运动对其成像产生的影响。针对运动目标的回波特点,介绍了利用分数阶傅里叶变换实现运动目标参数估计的原理和实现方法;(2)详细阐述了DPCA(Displaced Phase Center Antenna)和ATI(Along Track Interferometry)进行运动目标检测的原理,分析了这两种方法与分数阶傅里叶变换(Fractional Fourier Transform,FrFT)相结合实现参数估计的方法。针对已有的三通道方法在必须通过三个通道实现参数估计方面的局限,提出了改进的双通道DPCA-FrFT方法和改进的双通道DPCA-ATI-FrFT方法,理论和实验均表明这两种改进方法可以在所需通道数更少的情况下,实现很好的运动目标检测和参数估计。(3)在分析了空时自适应处理(Space-Time Adaptive Processing,STAP)的基本原理基础上,详细阐述了多通道SAR-STAP方法,并推导了联合FrFT实现参数估计的原理和方法。针对现有的多通道SAR-STAP运算量大的问题,提出了联合低分辨率粗检测和高分辨精细检测两个过程,改进的运动目标检测的频域STAP方法可以有效的减少计算量。
[Abstract]:Multi-channel SAR-GMTI technology can realize moving target detection and high-resolution radar imaging, which has important military and civilian value. It is one of the hotspots in the theory and application of SAR system. In this paper, the problem of moving target detection and parameter estimation based on multi-channel SAR and time-frequency analysis theory is studied deeply. The research work and the results obtained are as follows: 1) based on the echo model of moving target, the echo model of moving target is constructed, and the influence of target motion on its imaging is analyzed in depth. This paper introduces the principle and method of parameter estimation of moving object using fractional Fourier transform (FRT). The principle of moving target detection based on DPCA(Displaced Phase Center Antenna and ATI(Along Track interferometry is described in detail. This paper analyzes the two methods to realize parameter estimation by combining Fractional Fourier transform (FrFT) with Fractional Fourier transform (FrFT). In view of the limitations of the existing three-channel methods in realizing parameter estimation through three channels, The improved two-channel DPCA-FrFT method and the improved two-channel DPCA-ATI-FrFT method are proposed. The theoretical and experimental results show that the two improved methods can be used in the case of fewer channels. On the basis of analyzing the basic principle of space-time adaptive processing Space-Time Adaptive processing (STAP), the multi-channel SAR-STAP method is described in detail. The principle and method of parameter estimation based on joint FrFT are deduced. Aiming at the problem of large computation of multi-channel SAR-STAP, two processes of combined low resolution coarse detection and high resolution fine detection are proposed. The improved frequency-domain STAP method for moving target detection can effectively reduce the computational complexity.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN957.52

【参考文献】