【作者】 刘建新；

【导师】 向敬成； 汪学刚； 陈惠连；

【作者基本信息】 电子科技大学 ， 信号与信息处理， 2004， 博士

【摘要】 弹载雷达高度表具有与传统雷达和传统雷达高度表不同的特点。其主要表现在目标回波时域波形(脉冲)的展宽和宽的多普勒频谱。如此特点也决定了其目标检测与处理方法会有所不同。 传统的弹载脉冲雷达高度表(非相干)目标检测算法大都借助于点目标的二进制积累检测方法。算法的简单移植,使其在自动检测性能方面存在不足。因此,基于对雷达高度表面目标的二进制积累检测算法的研究显得尤为重要。就此本文提出了两种满足不同性能要求的检测算法,同时给出了相应的算法性能分析工具。 随着对大地回波频域等特征研究的进一步深入,为弹载脉冲多普勒雷达高度表的研究提供条件。传统弹载脉冲多普勒雷达高度表大都采取了距离、速度二维选通处理方法。尽管通过对较宽频带范围的多普勒信号的能量进行积累平均,但较宽的多普勒滤波器带宽极大限制了其信号检测处理性能的提高,固定的多普勒滤波器带宽也大大降低高度表应用的灵活性。同时为避免速度模糊而引入高重频脉冲致使测高模糊增加。除此之外,简单脉冲多普勒体制高度表也很难满足现代复杂电磁环境下抗干扰能力的要求。因此,寻找一种有效的脉冲多普勒雷达高度表波形和与此相应的高性能目标检测处理算法是本文研究的另一个重点。因此,本文给出了一种新的雷达高度表波形——高重频脉间二相编码信号。通过对高重频脉间二相编码波形及其高度表目标回波信号的分析研究,提出了三种不同的目标检测、处理算法。在此基础上,设计、实现了基于频域多普勒滤波峰值检测的目标检测处理系统。处理算法硬件测试结果表明:该编码波形和信号处理算法完全满足弹载雷达高度表总体设计要求。 为了客观评估脉间二相编码雷达高度表目标检测处理算法及其硬件的性能,提出了基于大地目标回波仿真的雷达高度表正交基带回波模拟系统,并完成该系统的设计、实现。 本文完成的主要工作有: 1.对垂直入射条件下,宽波束脉冲雷达高度表回波模型、距离域以及多普勒域回波特征进行全面的分析研究,据此对脉冲雷达高度表非相干积累检测和相更多还原

【Abstract】 Airborne radar altimeter, as a special applied domain, has different operation characteristics from conventional radar and radar altimeter. Time waveform and Doppler spectrum spread are significant points. Such characteristics will lead to different signal detection and processing methods.Researching on ground echo model and its distinctions of time domain are relative maturity in airborne incoherent pulse altimeters, incoherent pulse system is popular in early-stage(at present, such system is widespread availability).Corresponding algorithm adopted in target detection and processing borrows ideas from classical point-based target’s pulse radar system, such as: The binary integration detection (BI or M/N detection or double threshold detection) etc. Such simple algorithms transplant will make radar altimeter’s target detection performance fall down. So studying on area target’s detection algorithms for airborne pulse radar altimeter seem to be important. The content concerned is one of the tasks of this dissertation.Along with the technical development in modern radar and further researches on ground echo frequency domain characteristics, all achievements are prerequisite for developing airborne pulse Doppler radar altimeter. At the present, range correlation and velocity filtering processing methods are adopted in most of modern airborne pulse Doppler radar altimeters. Having wide Doppler filter width comparing to airborne pulse Doppler radar Doppler filter, signal processor has low performance. Meantime, it is fixed Doppler filter band that restrict airborne altimeter’s flexibility. On the other hand, high repeat frequency for avoiding measuring velocity blurriness leads to high range blurriness. Moreover, simple pulse Doppler radar altimeter system can’t satisfy the demands for anti-jamming in complex electromagnetic environment. So studying on a kind of waveforms adapting to airborne pulse Doppler radar altimeter and corresponding signal processing algorithms is major task in this dissertation.In order to estimate performance of target detecting algorithm and its hardware Objectively, an orthogonal base-band echo simulator system based on ground echo simulation is put forward. And simulator system’s hardware design and implementation have been finished.Main contents in this dissertation include:1 After studying time and frequency domain echo model and its characteristics for airborne pulse radar altimeter in beam lobe vertical incidence, then target detection and processing algorithms for non-coherent and coherent integration are studied emphatically.2 According to altimeter echo pulse spread in distance, two types of target detection methods, multi-range gate BI detection & double integrator BI detection, are put forward. The former improve detection performance and measurement accuracy of height by means of optimizing weighting factor in adjacent range gate. And the latter has high performance with lower false alarm probability by block integrating. In addition, assessment of detection algorithm performance based on Markov chain is a unique feature.3 Through analyzing echo Doppler spectrum of airborne pulse radar altimeter, relative complete model of echo simulation and its simulation program is created. This program can simulate target echo signal from maximal beam-lobe illuminating circle and clutter loop from blurred range in different height. All these are important for target detection algorithms investigated.4 In response to requirement of radar altimeter’s target detection performance, a kind of high PRF inter-pulse m sequence binary phase-coded waveform which combines all advantages of coherent pulse train and m sequence binary phase-coded signal has been presented. Not only does the waveform satisfy pulse Doppler radar altimeter demands, but also has high range and velocity resolution and measuring precision. Meantime, this waveforms signal can solve velocity and range’s measuring blurriness better. On the other hand, high anti-interference performance can be obtained.5 Three types of target detection algorithms, including their performance and更多还原