【作者】 董明；

【导师】 司伟建；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2011， 硕士

【摘要】 空间谱估计技术具有测角精度高、角度分辨力强、不受瑞利限限制等优点。在航海、航空、民事通信、雷达电子对抗,水声声呐等方面有着广泛的应用前景。在如今雷达电子对抗领域尤其是被动测向方面,在新旧测向体制同时存在、电磁环境日趋复杂以及对雷达诱饵进行多目标测向等情况下,对空间谱估计技术进行研究有着重要的意义。本课题在结合工程应用的背景下,对被动雷达测向系统中的测向方法进行研究,着重研究多目标的高精度、高分辨测向方法。通过对已有的空间谱估计算法进行分析和改进,实现改进算法在精度和分辨性能上的提高。首先,介绍了被动测向技术中相位干涉仪测向技术的原理,简要分析了该技术中的相位模糊和测角精度等相关问题,并通过数学推导建立起非相干两点源下比相体制干涉仪进行动态测向的数学模型,实验仿真结果给出了在非相干两点源下比相干涉仪动态测向的性能,证明了干涉仪测向技术不具有分辨多目标的能力。为此,引入了空间谱估计测向技术,并以谱估计技术中的经典MUSIC算法为主要研究对象,给出了天线阵列接收信号典型的数学模型,包括一维线阵和空间立体阵列模型。然后,针对经典MUSIC算法等相关算法存在的问题进行研究,通过一系列的理论分析和推导对经典MUSIC算法进行合理的改进,以实现测向精度和分辨力等性能的提高。接下来,在不同的仿真条件下,通过对不同形式的MUSIC算法和改进MUSIC算法进行Matlab仿真分析对比,仿真结果证明在低信噪比、小快拍数等条件下改进MUSIC算法具有更加优越的分辨性能。最后,结合工程实际应用中的信号处理硬件测向系统,对改进MUSIC算法的软件设计流程及硬件原理进行了说明。并在实验室的条件下,对经典MUSIC算法和改进MUSIC算法进行了实际测试,通过对两者实测数据的分析对比,进一步证明改进MUSIC算法在分辨性能上的优越性,为工程实际应用提供了依据,满足预期的结果。更多还原

【Abstract】 Spatial spectrum has advantages of high precision, high resolution and it can break through the rayleigh limited. It could be widely used in the fields of navigation, aviation, radar electronic warfare, civil communication, aquatic sonar and so on. In the field of electronic warfare especially passive direction finding technique, it is highly significant to research spatial spectrum on the current condition of coexistence of old and new direction finding system, the complex electromagnetic environment and the need of multi-signals direction finding.In this paper, based on the actual project application, some typical direction finding methods in passive radar direction finding system are researched especially the methods of high precision and high resolution algorithms.By researching the typical algorithms, a new modified algorithm is proposed with high precision and high resolution. First, it introduces the principle of direction finding technique with phase interferometer. The reason which causes the phase ambiguity and the facts which affect the precision of direction finding are analyzed briefly. And the mathematical model of phase comparison passive radar seeker angle measurement with decoy of no-coherent source is buided by mathematical deduction.Then it is proved that the method of phase interferometer has no effectiveness when there are more than two signals. Second, the spatial spectrum estimation direction finding techniques are introduced. The MUSIC algorithm which is a algorithm of the spatial spectrum estimation is researched in detail. And the typical mathematical model of the signal received by spatial array is given, such as the one-dimensional linear array and solid array. Then by the study of the MUSIC algorithm and the corresponding algorithms, a new modified MUSIC algorithm is proposed through analysis and deduction. The new algorithm has the advantages of higher precision, higher resolution than the MUSIC algorithm and the corresponding algorithms. Third, under the different condition these algorithms are simulated by Matlab, the results could be analysised and compared. Then the conclusion could be got that the performance of the modified MUSIC algorithm is better than the MUSIC algorithm and the corresponding algorithms when the SNR is lower and the snapshots is smaller. Finally, according to the engineering practice the principle of hardware and the design of software algorithm are illuminated in detail. And the whole direction finding system is tested in the laboratory environment, and by analyzing the test data it indicates that the modified MUSIC algorithm has excellent performance and it could provide a biasis for application in engineering. It achieves the desired results.更多还原