【作者】 权明吉；

【导师】 卢再奇； 范红旗；

【作者基本信息】 国防科学技术大学 ， 信息与通信工程， 2011， 硕士

【摘要】 现代战争中大量使用隐身飞机、反辐射导弹、巡航导弹等飞行器。它们的雷达回波能量比传统飞行器微弱得多，信噪比很低，传统的检测算法难以获得满意的检测性能。通过增大发射功率、提高天线孔径的方法虽然可以改善信噪比，但是具体实现上会受到诸多现实条件的限制，工程实现难度很大，甚至不可行。因此，从频域、时域、空域挖掘目标更多有用信息，并通过先进的信号处理实现弱小信号的检测成为必要的技术途径。本文针对单脉冲PD雷达弱小目标检测问题，充分挖掘了雷达三个通道中的信息，并综合利用有助于区分目标和噪声的信息(如角误差、复角相位、航迹等)进行了检测判决，有效提高了雷达的检测能力。本文的主要内容包括以下几个方面。绪论部分在介绍课题背景及研究意义的基础上，简要介绍了单脉冲和PD雷达的概念及其工作原理，并阐述了国内外研究现状及研究动态。第二章为单脉冲PD雷达信号检测的基本方法。在给出单脉冲PD雷达回波信号接收模型的基础上，介绍了该体制下的信号检测典型流程；分析总结了噪声背景下弱小目标检测技术的特点，提出了解决问题的几种可能方法和思路。第三章为差通道信息辅助的弱小目标检测算法。首先，分析了单脉冲体制下测角误差的分布特性，探讨了增大目标信号和噪声角误差分布差异的可能途径；然后，利用角误差分布差异特征构造了检验统计量，并在非相参积累检测算法的基础上，增加了检验统计量辅助检测支路，仿真结果表明新算法在一定程度上提高了非相参积累检测算法的性能。差通道中除了角误差信息外，还存在复角相位信息，这也是目标有用信息之一。因此，本章还设计了以归一化的信号幅度、角误差和复角相位为输入的神经网络目标检测算法。该算法试图综合利用雷达三通道有用信息，通过概率神经网络强大的分类能力达到更好的区分目标和噪声的目的。仿真结果表明该算法与非相参积累检测算法相比具有更优的性能。第四章为基于DP-TBD的高重频PD雷达检测算法。首先，介绍了目标运动模型和观测模型；然后，阐述了基于动态规划的TBD算法原理及流程，并提出了高重频模式下的DP-TBD算法；最后，结合第三章中的角误差信息，设计了在角误差-多普勒-时间三维空间上的DP-TBD算法，仿真结果表明新算法能进一步提高检测性能。更多还原

【Abstract】 The flyers, such as stealth aircraft, Anti radiation Missile, and Cruise Missile and so on, are widely used in modern war. The radar echoes of them are much weaker than those of traditional flyers. The signal to noise ratio(SNR) is too low to detect target reliably with general algorithms. Although by increasing the transmitter power, antenna aperture would improve SNR, the concrete realization is always subject to many reality conditions, the project implementation is very difficult, even impossible. Therefore, digging more useful target information from Frequency domain, Time domain and Spatial domain, and through advanced signal processing to detect weak target become necessary technical meansThe dissertation focuses on the problem of weak target detection with Monopole Doppler radar. In this paper, we fully use helpful information of three channels of radar (such as the angle error, complex phase angle and track etc.) to distinguish target from noises. New algorithms effectively improve radar’s detection capability. This paper mainly covers the following aspects:Chapter 1 introduces the background and significance of the problem to be studied, and briefly introduces the concept of Monopulse and PD radar besides their working elements. At last the corresponding techniques and research trends at home and abroad are described.Chapter 2 is the signal detection basic theory of Monopulse PD radar. Firstly, the signal echo receiving model of Monopulse PD radar is presented, then introduces the typical flow of signal detection under the system. Finally, analyzes and summarizes the characteristics of weak target problem, proposes several possible methods to solve the problem.Chapter 3 is the new algorithm designing which is based on difference channel information. Firstly, the analysis of angle error measurement under Monopulse system is proposed, and the possible way of increasing the difference of angle distribution between the target and noises is discussed. Secondly, the test statistic based on angle error is constructed, and in the traditional non phase coherent integration algorithm, the test statistic auxiliary detection branch is added. The simulation results show that the new algorithm improves performance of primary non coherent detection algorithm. In addition to angle error information, difference channel also have phase information, which is useful information for detection too. Therefore, dim target detection algorithm based on neural network of which inputs are normalized signal amplitude, angle error and phase of angle is proposed. New algorithm attempts to make fully use of three channel information, and combine the powerful classification ability of probabilistic neural network to better distinguish between the target and noise. Simulation results show that the algorithm has better performance compared with non coherent integration algorithm.Chapter 4 is Track Before Detect algorithm based on dynamic programming in high PRF PD radar. Firstly, target motion model and observation model are briefly introduced. Secondly, the principles and processes of TBD algorithm based on dynamic programming are described, and DP TBD algorithm in HPRF mode is proposed. At last, with the angle error information a new DP TBD algorithm which process in the Angle Doppler Time three dimensional space is proposed, Simulation results show that the new algorithm can further improve the detection capability.更多还原