高频地波雷达方位超分辨算法的研究

发布时间：2017-12-28 01:14

本文关键词：高频地波雷达方位超分辨算法的研究　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：相比于传统雷达,高频地波雷达拥有探测距离远、能提供大范围的早期预警、预警时间远远超出普通雷达的独特优势,具有重要的国防、政治、军事、经济价值。然而受海边实际天线阵地大小的限制,接收阵列孔径的长度极为有限,导致高频地波雷达的角度分辨率性能较差。本文主要针对理想阵列以及非理想阵列状态下的高频地波雷达的方位超分辨算法进行研究。主要的工作内容如下:1.对高频地波雷达的接收信号工作原理进行了理论分析,引出目标方位信息的提取过程。对现有的几种经典的应用比较广泛的超分辨算法进行性能分析和比较,同时用高频地波雷达的实测数据验证了MUSIC算法的性能。2.针对高频地波雷达的角度分辨率受限于阵列孔径的问题,而传统的算法又很难突破这个瑞利限,基于此,本文提出了一种新的外推模型—AR循环外推,来解决这个问题。该方法通过采用改进的AR循环外推模型增加接收数据长度的方法来虚拟增加阵列孔径从而实现超分辨。相比于传统的超分辨算法,该模型能对单快拍下的接收回波数据进行合理外推,不仅提高了单快拍下的测角精度,还提高了角度分辨率。计算机仿真试验以及采用雷达的实测数据仿真都验证了该模型的有效性。3.以上讨论的超分辨算法都是在理想阵列流型下,即阵列不存在误差,阵列的导向矢量精确已知的前提下实现的,然而在实际应用中,不可避免会出现阵列误差,所以需要对非理想阵列状态下的DOA估计性能进行分析。给出了阵列响应误差的模型,对误差的影响进行了理论和仿真分析。对阵列响应误差的三种典型校正算法进行了性能比较,基于种种原因,高频地波雷达系统常常采用自校正技术,针对传统的自校正技术存在的缺陷,提出了一种组合算法。该算法采用基于协方差矩阵的无源校正算法与迭代法相结合,将前者的估计值作为自校正的初始值,然后进行迭代,直至收敛。先用初值预处理后的迭代法对阵列的幅相误差进行校正补偿,然后再利用改进的AR-MUSIC算法提高高频地波雷达的方位分辨率。计算机仿真实验验证了该方法的有效性。
[Abstract]:Compared with the traditional radar, HF ground wave radar has the advantages of wide detection range and wide range of early warning and warning time, which is far beyond the ordinary radar. It has important national defense, political, military and economic values. However, limited by the size of the actual antenna position by the sea, the length of the received array aperture is very limited, which leads to the poor angular resolution performance of the high frequency ground wave radar. This paper mainly studies the azimuth superresolution algorithm of high frequency ground wave radar under the state of the ideal array and the state of the non ideal array. The main contents are as follows: 1. the principle of the receiving signal of high frequency ground wave radar is analyzed theoretically, and the extraction process of target orientation information is brought out. The performance of several classic super-resolution algorithms is analyzed and compared. At the same time, the performance of MUSIC algorithm is verified by the measured data of HF ground wave radar. 2., the angle resolution of HF ground wave radar is limited by the aperture of the array, and the traditional algorithm is hard to break through the Rayleigh limit. Based on this, a new extrapolation model, AR cycle extrapolation, is proposed to solve this problem. In this method, an improved AR loop extrapolation model is used to increase the length of the received data to virtual increase the aperture of the array to achieve superresolution. Compared to the traditional super-resolution algorithm, the model can receive the echo data of a single snapshot of the reasonable extrapolation, not only improves the accuracy of single snapshot, but also improve the angle resolution. The effectiveness of the model is verified by the computer simulation test and the simulation of the measured data using radar. 3. super resolution algorithms discussed above are in the ideal array manifold, i.e. there are no array errors, the premise of the steering vector of the array to achieve precisely known, but in practical application, inevitably there will be error of the array, so the need for a non ideal array under the condition of DOA estimation performance analysis. The model of array response error is given, and the influence of the error is analyzed theoretically and simulated. The performance of three typical correction algorithms for array response error is compared. For various reasons, self correcting technology is often adopted in HF ground wave radar system, aiming at the shortcomings of traditional self-tuning technology, a combinatorial algorithm is proposed. The algorithm combines the passive correction algorithm based on covariance matrix with the iterative method, and takes the estimated value of the former as the initial value of self-tuning, and then iterates until convergence. The amplitude and phase errors of array are corrected and compensated by the iterative method after the initial value is preprocessed, then the azimuth resolution of HF ground wave radar is improved by using the improved AR-MUSIC algorithm. The effectiveness of the method is verified by computer simulation experiments.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN958

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