【作者】 李保国；

【导师】 郭桂蓉；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2005， 博士

【摘要】 目标角闪烁是制约末制导雷达跟踪和命中精度的主要因素。如何抑制角闪烁、改善末制导雷达的测角精度、提高末制导雷达在角闪烁背景下的跟踪制导精度,一直是雷达精确制导武器研制人员格外关心的问题;另一方面,从角闪烁的产生机理可知,角闪烁线偏差是一种典型的目标特征信号,其中蕴含了丰富的目标信息,因此在高分辨雷达利用目标一维距离像进行目标识别的过程中,能否将扩展目标的角闪烁信息加以利用,达到提高雷达自动目标识别性能的目的,也是颇为值得探讨的问题。本文针对以上问题展开研究,详细探讨了光学区末制导雷达扩展目标的角闪烁建模、角闪烁抑制、角闪烁背景下的目标跟踪与基于角闪烁特性的目标识别等方面的理论和应用技术,主要内容如下: 首先在绪论中概述了雷达精确制导信息处理的重要课题;然后概述了角闪烁信息处理技术的研究现状;最后指出了本文研究的出发点和思路,并介绍了本文所做的主要工作。 第二章主要研究捷变频雷达中抑制角闪烁、改善测角精度的理论方法。论文首先给出了基于扩展目标多散射中心模型的角闪烁仿真建模方法,在此基础上研究了频率捷变对目标回波幅度的去相关性能以及对目标角闪烁的去相关性能,给出了频率捷变去相关必须满足的条件。随后本文详细研究了各种加权函数的角闪烁抑制性能,并证明了幅度平方加权函数在整数幂次加权函数中的最优性,在此基础上提出了一种基于幅度平方加权(SAW,square amplitude weighting)的非相参积累改善测角精度的方法,给出了仿真实验结果。此外,本文基于ABA(amplitude based angle)处理的思想,对经典的单脉冲测角方法进行了改进,给出了单脉冲雷达天线设计的最优准则,再结合幅度平方加权的方法,提出了一种基于ABA+SAW处理的角闪烁抑制方法。 第三章主要研究了频率步进合成宽带雷达中的测角方法和角闪烁背景下的跟踪滤波问题。首先介绍了利用频率步进合成宽带雷达实现距离间隔一维成像的原理,详细分析了高分辨距离间隔像的性质,包括其分辨率、不模糊间隔以及不受运动影响的条件。然后提出了三种过采样条件下基于距离间隔像的单脉冲雷达测角新方法,并证明了交叉项取大法(selecting the largest of cross entries,SLCE)的最优性。本章的后半部分,主要研究了角闪烁背景下基于粒子滤波器的末制导跟踪算法,通过仿真实验证明该算法性能大大优于基于扩展卡尔曼滤波(EKF)的角跟踪算法。更多还原

【Abstract】 Target glint is the main factor which influences tracking and guidance accuracy of terminal guidance radar. Researchers on radar precision guidance weapon pay much attention to suppress glint, improve angle measuring accuracy and improve guidance radar’s tracking and guiding accuracy. On the other hand, it is well known from the glint generation mechanism that target line glint error is also a target signature and it contains plenty of target information. So it is valuable to use target glint to enhance the performance of target recognition by high resolution range profile. In this paper, the theory and some applicational technologies about target glint for terminal guidance radar in optical region, including glint simulation, glint suppressing, target tracking with glint, target recognition using glint, are discussed in detail. The main work is outlined as follows.In chapter 1, radar precision guidance and its critical technology are clarified. Then the current status of the study on target glint is introduced. At the end of this part, the main works of this paper are outlined.In chapter 2, the theories and technologies of suppressing glint and improving angle measuring accuracy for frequency agility radar are studied. Firstly, the feasibility of glint simulation using multiple-scattering-centers target model is studied. Based upon this model, the decorrelation performance for target echo amplitude as well as the decorrelation performance for target glint of frequency agility radar is studied and the decorrelation frequency condition is verified. Secondly, a study on glint suppressing algorithm is performed based on amplitude weighting. Peformance comparison under different integer power amplitude weighting is made and the optimization of square amplitude weighting is proved. A kind of noncoherent integration angle measuring method based on SAW (square amplitude weighting) is developed. Finally, a new monopulse radar angle measuring algorithm based on ABA (amplitude based angle) plus SAW processing is presented. This algorithm takes ABA processing instead of common monopulse radar angle extraction method, and use amplitude weighting to further process the measured angle data. The optimal region principle is presented for monopulse radar antenna design.In chapter 3, the angle measuring method for stepped frequency radar and target tracking with glint are studied. Firstly, a systematic study is performed on high resolution range separation profile for stepped-frequency radar. The range resolution, unambiguous rangeseparation and the accuracy of motion compensation are analyzed in detail. The principle for high resolution range separation profile angle measuring is clarified. Then three angle measuring algorithms based on high resolution range separation profile are developed under oversampling conditions. SLCE method (selecting the largest of cross entry) is proved to be optimal through computer simulation. Secondly, a study is performed on the application of particle filter for tracking with glint noise. Monte-Carlo simulation proves that the performance of particle filter is far superior to EKF for tracking with glint noise.In chapter 4, the application of target glint signature in high resolution radar target recognition is studied. Firstly, the concept of "distributed glint" is put forward; the expression of "distributed glint" is deduced. Secondly, a new target recognition algorithm based on range profile and distributed glint is developed. Finally, a practical target recognition algorithm based on wavelet decomposition and BP neural networks is developed. Computer simulation verifies the performance of this algorithm.In chapter 5, all the work in this paper is summarized and related conclusions are presented, together with further research to be done.更多还原