船载高频地波雷达海洋表面流遥感方法研究

发布时间：2019-06-02 05:08

【摘要】：高频地波雷达(High Frequency Surface Wave Radar,HFSWR)利用垂直极化高频电磁波(3~30MHz)可实现对海上舰船、低空飞机等目标的超视距探测以及对海洋表面状态信息(如海流、风场以及浪高等)进行大范围、全天候的海态遥感。船载HFSWR是岸基HFSWR技术的深入与发展,除继承了岸基雷达的优点外,其主要特点表现为船载平台的灵活机动性。利用此特点,船载HFSWR可快速前往感兴趣海域开展目标探测或海态遥感作业。因此,船载HFSWR在军事和民用领域都有着广泛的发展前景和应用价值。目前基于岸基HFSWR的海态遥感理论及应用技术比较成熟,国内外均已研制成功多种岸基HFSWR系统并得到推广应用。但基于船载HFSWR的海态遥感理论和应用技术的研究基本属于空白。本文以船载HFSWR为研究平台,以海洋表面流为研究对象,开展船载HFSWR海洋表面流遥感方法研究。本文研究成果将为我国开展船载HFSWR海态遥感研究提供新的理论依据和方法,对无线电海洋学的深入研究和发展具有重要的意义。本文主要研究内容如下:1.简要介绍岸基HFSWR海洋表面流遥感的基本原理,并在此基础上分析船载HFSWR海浪回波信号多普勒谱展宽的机理以及船载HFSWR应用于海洋表面流遥感所需解决的主要问题,即海洋表面径向流的波达方位(Direction-of-Arrival,DOA)估计、海浪回波信号空时耦合以及单站海洋表面矢量流估计问题。2.针对船载HFSWR海洋表面径向流方位估计中存在阵元数少、可用快拍数据有限、展宽的海浪回波多普勒谱中容易出现目标信号的问题以及复值稀疏表示方法普遍存在重构精度低和计算量大的问题,首先理论分析船载HFSWR海浪回波信号在单个距离和多普勒分辨单元内的稀疏性,然后研究基于实值阵列信号和实值阵列信号协方差阵稀疏表示的两种DOA估计方法;最后通过计算机仿真结果和实测船载HFSWR数据处理结果验证这两种实值稀疏表示方法的有效性。3.针对船载HFSWR海浪回波信号存在空时耦合的问题,首先理论分析船载HFSWR海浪回波信号的特征谱及其分布特性,研究一种船载HFSWR海浪回波信号协方差阵秩(即海浪回波信号特征谱中大特征值的个数)的估计方法;然后利用该方法对船载HFSWR海浪回波信号在整个空时二维联合域中的稀疏性进行理论分析,重点研究一种基于实值稀疏表示的空时二维多重信号分类(MUltiple SIgnal Classification,MUSIC)方法,并将其应用于船载HFSWR海浪回波信号空时二维谱估计;最后通过计算机仿真分析验证船载HFSWR海浪回波信号协方差阵秩估计方法和基于实值稀疏表示的空时二维MUSIC方法的有效性。4.针对单站HFSWR难以直接获取海洋表面矢量流的问题,理论分析海洋表面矢量流场分布特性和船载HFSWR海洋表面径向流测量误差的分布特性,研究一种基于一阶流函数的单站船载HFSWR海洋表面矢量流估计方法,并通过计算机仿真分析验证该方法在均匀流场和非均匀流场条件下的有效性。
[Abstract]:High Frequency Surface Wave Radar (HFSWR) makes use of the vertical polarized high-frequency electromagnetic wave (3-30 MHz) to realize the over-the-horizon detection of targets such as marine vessels and low-altitude aircraft, as well as the large range of information on the surface state of the ocean (such as current, wind field and wave, etc.). All-weather sea-state remote sensing. The ship-borne HFSWR is an in-depth and development of the shore-based HFSWR technology. In addition to the advantages of the land-based radar, the ship-borne HFSWR is characterized by the flexible mobility of the ship-borne platform. With this feature, the shipboard HFSWR can quickly go to the area of interest to carry out the target detection or the sea-state remote sensing operation. Therefore, the shipboard HFSWR has a wide development prospect and application value in the military and civil fields. At present, the sea-state remote sensing theory and application technology based on the shore-based HFSWR are relatively mature, and a variety of shore-based HFSWR systems have been successfully developed at home and abroad. But the research of the sea-state remote sensing theory and the application technology based on the shipborne HFSWR is basically a blank. In this paper, the ship-borne HFSWR is used as the research platform, and the sea surface flow is used as the research object to carry out the research of the ship-borne HFSWR ocean surface flow remote sensing method. The research results of this paper will provide a new theoretical basis and method for carrying out the shipborne HFSWR sea-state remote sensing research, which is of great significance to the deep research and development of radio oceanography. The main contents of this paper are as follows:1. The basic principle of the sea surface flow remote sensing of the shore-based HFSWR is briefly introduced, and on the basis of this, the mechanism of the Doppler spectrum broadening of the shipborne HFSWR wave echo signal and the main problems for the application of the ship-borne HFSWR to the remote sensing of the marine surface flow are analyzed, that is, the direction of arrival of the radial flow of the ocean surface (Direction-of-Arrival, DOA estimation, space-time coupling of sea wave echo signals, and estimation of vector flow for single-station ocean surface. Aiming at the problem that the number of the array elements is small in the radial flow direction estimation of the ship-borne HFSWR ocean surface, the problem that the target signal is easy to appear in the Doppler spectrum of the spread sea wave echo and the problem that the reconstruction precision is low and the calculation amount is large are common in the extended sea wave echo Doppler spectrum, Firstly, the sparsity of the ship-borne HFSWR wave echo signal in a single distance and a Doppler-resolving unit is analyzed, and two DOA estimation methods based on the sparse representation of the real-value array signal and the real-value array signal covariance matrix are then studied. And finally, the validity of the two real-value sparse representation methods is verified by the computer simulation result and the measured ship-borne HFSWR data processing result. Aiming at the problem of space-time coupling of the shipborne HFSWR wave echo signal, the characteristic spectrum and the distribution characteristic of the shipborne HFSWR wave echo signal are firstly analyzed, A method for estimating the rank of a ship-borne HFSWR wave echo signal covariance matrix (that is, the number of large characteristic values in the wave echo signal characteristic spectrum) is studied, and then the sparsity of the ship-borne HFSWR wave echo signal in the whole space-time two-dimensional joint domain is analyzed by using the method, In this paper, a space-time two-dimensional multi-signal classification (MUSIC) method based on sparse representation of real-value is studied, and it is applied to the space-time two-dimensional spectral estimation of ship-borne HFSWR wave echo signals. Finally, a computer simulation analysis is used to verify the validity of the ship-borne HFSWR wave echo signal covariance matrix rank estimation method and the space-time two-dimensional MUSIC method based on the real-value sparse representation. aiming at the problem that the single-station HFSWR is difficult to directly acquire the ocean surface vector flow, the distribution characteristics of the marine surface vector flow field and the distribution characteristics of the ship-borne HFSWR ocean surface radial flow measurement error are analyzed theoretically, a single-station shipborne HFSWR ocean surface vector flow estimation method based on the first-order flow function is researched, And the effectiveness of the method under the conditions of uniform flow field and non-uniform flow field is verified by computer simulation analysis.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：P715.7;TN959

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