《高频段电离层特性及雷达综合频率选择方法研究优秀毕业论文》由会员分享，可在线阅读，更多相关《高频段电离层特性及雷达综合频率选择方法研究优秀毕业论文（70页珍藏版）》请在金锄头文库上搜索。
1、 - 硕硕士学位论文士学位论文 （工程硕士）（工程硕士） 高频段电离层特性及雷达综合频率选择方法 研究 RESEARCH ON IONOSPHERIC CHARACTERISTICS AND INTEGRATED RADAR FREQUENCY SELECTION METHODS OVER HIGH FREQUENCY BAND 张文敏张文敏 哈尔滨工业大学哈尔滨工业大学 2011 年年 6 月月 - 国内图书分类号：TN958.93 学校代码：10213 国际图书分类号：621.396.96 密级：公开 工工程程硕硕士学士学位论文位论文 高频段电离层特性及雷达综合频率选择方法 研究 硕 士
2、研 究 生 ： 张文敏 导 师 ： 杨强副教授 申请学位 ： 工程硕士 学科、 专业 ： 电子与通信工程 所 在 单 位 ： 电子与信息工程学院 答 辩 日 期 ： 2011 年 6 月 授予学位单位 ： 哈尔滨工业大学 - Classified Index: TN958.93 U.D.C: 621.396.96 Dissertation for the Master Degree in Engineering RESEARCH ON IONOSPHERIC CHARACTERISTICS AND INTEGRATED RADAR FREQUENCY SELECTION METHODS OVE
3、R HIGH FREQUENCY BAND Candidate： Zhang Wenmin Supervisor： Prof. Yang Qiang Academic Degree Applied for： Master of Engineering Speciality： Electronics and Communication Engineering Affiliation： School of Electronics and Information Engineering Date of Defence： June, 2011 Degree-Conferring-Institution
4、： Harbin Institute of Technology 哈尔滨工业大学工程硕士学位论文 I 摘 要 高频地波雷达作为一种新体制雷达，除了具有更加优良的探测性能之外也有 它的局限性和缺点，这主要表现在它在高频段的生存能力。高频雷达工作在复杂 的电磁环境中，各种干扰和噪声都和工作频率有关。除此之外，雷达目标散射截 面积和地波传播衰减特性也和雷达工作频率有关。实际工作中如果选频不当会导 致雷达检测不到目标或者探测距离降低。本论文主要研究内容就是综合以上各种 因素考虑高频地波雷达频率优化选择问题，建立了以最大信杂噪比为准则函数的 高频雷达频率优选系统，设计实现了高频地波雷达频率优化选择界面系
5、统。主要 研究内容如下： 首先，电离层干扰是影响高频雷达频率优化选择的重要因素。本文介绍了电 磁波的电离层传播机理，预测了电离层每一层穿透频率特性和峰值高度特性，分 析了电离层吸收损耗特性。分析了电离层回波对高频地波雷达的影响，提出了电 离层杂波干扰可能的几种传播模式。 其次，推导了高频地波雷达雷达方程，研究了高频电磁波沿均匀光滑海面传 播时的传输衰减特性，分析了给定雷达目标的散射截面积特性。 再次，通过对电离层回波干扰中的几条可能回波路径的分析，提出了电离层 回波干扰四种工作模式以及它们的组合模式的概念。仿真分析了两种电离层传播 模式下电离层回波干扰路径，以及各个路径的传播损耗，并应用后向返
6、回散射能 量算法计算了目标距离单元内的电离层回波能量。预测了环境噪声系数，环境噪 声一般随频率增大而减小。讨论了海杂波对回波信号的影响，重点讨论了一阶海 杂波对目标的遮挡问题，通过对二阶散射系数的讨论介绍了二阶海杂波能量的计 算方法。 最后，介绍了高频地波雷达频率优选系统的构成，建立了最大信杂噪比的频 率优选准则。分别介绍了每一部分具体的计算及实现流程，最后给出了高频地波 雷达优选系统的选频计算总流程。基于最大信杂噪比准则设计实现了高频地波雷 达频率优选系统以及其界面显示系统。 关键词关键词：电离层；高频地波雷达；信杂噪比；频率优化选择；显示界面 哈尔滨工业大学工程硕士学位论文 II Abst
7、ract As a new radar system, high-frequency surface wave radar has more excellent detection performance but inevitable has its limitations and shortcomings, mainly reflected in failing to survive in the high frequency band. High frequency radar work in complex electromagnetic environment, various kin
8、ds of interference and noise are frequency related. In addition, the radar target cross section and surface wave propagation attenuation characteristics are also related to the radar operating frequency. Improper frequency selection will lead to the radar leakage alarm and detection range reduced. T
9、he main contents of this paper is to consider the above factors impacting on optimization of work frequency in high frequency ground wave radar, a maximum SCNR criteria are established as a optimal function for high-frequency surface wave radar systems. Design and archive user interface system for o
10、ptimization of work frequency in high-frequency surface wave radar . The main contents are as follows: First, ionospheric disturbances are an important factor in the optimal frequency system of high-frequency surface radar. This article describes the mechanism of electromagnetic waves propagation in
11、 the thermosphere, the critical frequency and peak height of each layer will be predicted. Ionospheric absorption loss characteristics and ionospheric echoes of high frequency surface wave radar will be discussed. Several possible mode of transmission are proposed. Second, we firstly derive the High
12、 frequency surface wave radar equation, and then study Transmission attenuation characteristics of the high frequency electromagnetic wave propagation along the uniform and smooth sea. Finally, Radar cross section (RCS) of given radar target will be discussed. Third, through the study of several pos
13、sible echo routes in ionospheric echo interfere, we proposal the concept of four single working mode and the combination of the four in ionospheric echo interfere. Then we simulate echo interference route of the two ionospheric propagation mode, and the whole propagation loss of each path. Thirdly,
14、we use the backward scattering energy algorithm to compute the ionospheric echo energy in the target unit distance. we prediction environmental noise coefficient, environmental noise generally decreases with frequency increase. we also discuss the sea clutter impact of the echo signals, especially t
15、he first-order sea clutter occlusion on the target, introduce second-order sea clutter energy calculating method through the discussion of second-order scattering coefficient. Finally, we involve optimization structure of high-frequency surface wave radar frequency system, establish optimization fre
16、quency rule of the largest SCNR (Signal to Clutter and Noise Ratio). After introduced each part of the calculation and implementation processes, we finally gives the whole calculate process of frequency 哈尔滨工业大学工程硕士学位论文 III optimization system in high-frequency surface wave radar. In the end, the whole frequency optimization system and the GUI of high-frequency surface wave radar are archived. Keywords: ionosphere, high frequency surface wave ra
