调频步进雷达信号理论与应用研究

【作者】 郭俊芳；

【导师】 朱晓华；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2009， 硕士

【摘要】 高分辨率雷达在军事中有着极为广泛的应用。调频步进雷达信号兼有频率步进信号和Chirp信号的优点,是一种高距离分辨力信号。本文以毫米波雷达导引头为背景,针对宽带调频步进雷达信号的一维成像进行深入研究。首先,给出了宽带雷达信号具有高分辨能力的直观解释,推导了频率步进雷达合成高分辨一维距离像的通用数学表达式。对调频步进雷达信号进行了分析,研究了调频步进雷达信号的模糊函数、距离多普勒耦合特性和副瓣抑制问题。其次,介绍了调频步进雷达信号合成高分辨距离像的基本原理。对调频步进雷达脉内脉间两步压缩进行了深入分析。再次,对调频步进雷达信号的多普勒效应进行了分析和仿真,提出了先采用基于FFT的速度粗估计、再利用最小脉组误差准则的两步运动补偿方法。同时探讨了调频步进雷达信号距离像的混叠、冗余问题和距离像的拼接技术,研究了结合目标抽取和参数选取的方法解决距离像的混叠、冗余问题。最后,介绍了双平面振幅和差式单脉冲雷达测角方法,提出了基于高分辨距离像的测角方法,介绍了调频步进单脉冲雷达体制通过三通道(和通道、方位差通道、俯仰差通道)得到目标方位角和俯仰角的基本过程。更多还原

【Abstract】 High-resolution radar is widely used in military applications. Chirp-subpulse stepped frequency signal (CSSF) is one of the high range resolution signals with merits of stepped-frequency signal and chirp signal. This dissertation studies the one dimensional imaging method of CSSF in millimeter radar guidance system.First, the basic expression of high-resolution one dimensional range profile of the stepped frequency (SF) is deduced to explain the high resolution of the wideband signals. Then, the characteristic of CSSF is analyzed, and the ambiguity function, the coupling of range and Doppler frequency and the sidelobe suppression are studied.Secondly, the basic process to obtain high resolution range profile of CSSF is introduced in this paper. The two-step process with Intra-pulse compression and Inter-pulse compression is further studied.Thirdly, the Doppler effect of CSSF is analyzed and simulated. A new method for motion compensation of combined fast approximate estimation based on Fast Fourier Transformation and accurate search estimation based on the least burst error rule is proposed. Profile aliasing and redundance in CSSF are discussed, and resolved by the method which combines target pick-up and parameters-selecting algorithms.At last, A-SD mono pulse radar is introduced. A method of angle measurement based on high resolution range profile is proposed. The process of obtaining azimuth and elevation of CSSF mono pulse radar with three channels (sum channel, azimuth difference channel, elevation difference channel) is given.更多还原