米波雷达测角方法研究

发布时间：2018-11-08 11:53

【摘要】：米波雷达由于在反隐身,抗反辐射导弹等方面具有独特的优势,已成为了现今世界各国关注的焦点。但是由于米波雷达的波长较长,波束宽度较宽等因素的影响,目标角度估计的精度较差。所以如何提高米波雷达的测角精度,是当前米波雷达的一个重要研究方向。本文结合本人目前承担的科研任务及主要研究课题主要对米波雷达的测角方法进行了研究,并提出了几种改进的米波雷达测角算法:首先,对一些米波雷达基础的测角方法进行了研究,简单介绍了雷达测角的工作原理及一些基本的测角方法,主要包括振幅法、相位法、最大信号法、质心法及单脉冲类方法。并对这些方法的测角性能及优缺点进行计算机实验仿真,对这些方法存在的一些问题进行了讨论和分析,重点对单脉冲方法中的鉴角曲线进行了理论分析和数学推导。其次,对机扫米波雷达的工作原理和常规的单脉冲类测角方法的原理进行了介绍,在此基础上提出了两种改进的方法,分别是改进的单脉冲测角方法和改进的波束扫描方法。改进的单脉冲测角方法是根据半阵法原理,将接收的数据进行DFT运算转换到多普勒通道中,在多普勒通道中对其某些点进行置零处理,再进行IDFT运算,利用处理后的数据进行单脉冲测角;而改进的波束扫描方法则构建一个新的代价函数,此代价函数将以前的多次波束扫描简化为一次搜索就可以得到目标的角度信息,大大降低了运算量,仿真结果表明这两种改进算法的性能较常规算法更优。接着对分布式米波雷达的结构模型和基本原理进行了介绍,研究了基于ESPRIT算法的粗略估计方法和精确估计方法。粗略估计是分布式雷达的一种固有属性,利用粗略估计方法进行角度估计会得到方差较大、不存在测角模糊的估计值。相反,利用精确估计方法会得到方差较小、存在测角模糊的估计值,所以需要对估计值再进行最优搜索获得目标真实角度。理论分析和仿真实验表明,两种角度估计方法的测角性能都很高,其中精确估计方法的性能优于粗略估计方法。最后,根据分布式米波雷达的结构特点,进一步分析基线长度对测角精度造成的影响。随着基线长度的不断增加,分布式米波雷达的测角性能呈“V”型变化,针对分布式米波雷达随基线长度的性能变化特点,提出了一种最优基线长度确定方法。利用该方法可以确定最优的基线长度,降低分布式米波雷达因本身结构特点造成的测角误差,计算机仿真实验验证了该方法的有效性。
[Abstract]:Because of its unique advantages in anti-stealth and anti-radiation missiles, Mibo radar has become the focus of attention all over the world. However, due to the influence of long wavelength and wide beam width, the accuracy of target angle estimation is poor. Therefore, how to improve the angle measurement accuracy of Mew radar is an important research direction. In this paper, based on the research task and the main research subject, the angle measurement method of Mew radar is studied, and several improved angle-measuring algorithms are proposed: first of all, In this paper, some basic angle measuring methods of meter wave radar are studied. The working principle of radar angle measurement and some basic angle measuring methods are introduced, including amplitude method, phase method, maximum signal method, centroid method and monopulse method. The performance, advantages and disadvantages of these methods are simulated by computer experiments, and some problems of these methods are discussed and analyzed. The theoretical analysis and mathematical derivation of the angle detection curve in monopulse method are emphasized. Secondly, the working principle and the principle of the conventional monopulse angular measurement method are introduced, and two improved methods are proposed, one is the improved monopulse angle measurement method and the other is the improved beam scanning method. The improved monopulse angle measurement method is based on the principle of semi-matrix method, the received data is converted from DFT operation to Doppler channel, and some points of the received data are zeroed in the Doppler channel, and then the IDFT operation is carried out. Using the processed data to measure the angle of monopulse; The improved beam-scanning method constructs a new cost function, which simplifies the previous multi-beam scanning to a single search to obtain the angle information of the target, which greatly reduces the computational complexity. Simulation results show that the performance of the two improved algorithms is better than that of the conventional algorithms. Then, the structure model and basic principle of distributed meter wave radar are introduced, and the rough estimation method and accurate estimation method based on ESPRIT algorithm are studied. Rough estimation is an inherent attribute of distributed radar. Using rough estimation method to estimate the angle will result in a large variance and there is no fuzzy angle measurement value. On the contrary, using the accurate estimation method, the variance is smaller and the angle is fuzzy. Therefore, it is necessary to search the estimation value and obtain the real angle of the target. Theoretical analysis and simulation experiments show that the performance of the two methods is very high, and the performance of the accurate estimation method is better than that of the rough estimation method. Finally, according to the structural characteristics of distributed meter wave radar, the influence of baseline length on angle measurement accuracy is further analyzed. With the increasing of baseline length, the angle measurement performance of distributed meter wave radar changes in "V" type. According to the characteristic of distributed meter wave radar with baseline length, an optimal baseline length determination method is proposed. By using this method, the optimal baseline length can be determined and the angle measurement error caused by the structural characteristics of the distributed meter wave radar can be reduced. The effectiveness of the method is verified by computer simulation.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN953.5

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