Improving Surface Current Resolution Using Direction Finding Algorithms for Multiantenna High-Frequency Radars
Improving Surface Current Resolution Using Direction Finding Algorithms for Multiantenna High-Frequency Radars
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DOI：
10.1175/jtech-d-19-0029.1
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发表时间：
2019-10
影响因子：
2.2
通讯作者：
A. Kirincich;B. Emery;L. Washburn;P. Flament
中科院分区：
文献类型：
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作者：
A. Kirincich;B. Emery;L. Washburn;P. Flament
虽然陆基高频雷达是能够分辨沿海海洋表层流的时间和空间变异性的唯一工具，但最近的高分辨率观点表明，沿海海洋比目前部署的雷达系统能够揭示的更加复杂。为了提高高频雷达的方位分辨率，本工作采用了一种混合系统，该系统同时具有相控阵和测向雷达单元。来自部署在美国东海岸的两个雷达的数据被配置为8天线栅格阵列，用于评估潜在的测向和信号或发射器检测方法。在相同的发射器检测方法的情况下，诸如最大似然估计的测向方法通常比众所周知的多信号分类(MUSIC)方法表现得更好。然而，准确估计高频雷达观测中存在的辐射源的数量是一个挑战。由于MUSIC的波达方向(DOA)功能允许进行简单的经验测试，从而极大地帮助检测过程，因此在本研究中，MUSIC被发现是更好的方法。8天线阵列能够提供比典型的3天线系统更准确的MUSIC噪声子空间估计，不需要一系列经验参数来控制MUSIC的性能。为这项研究开发的代码已经在一个在线储存库中提供。
While land-based high-frequency (HF) radars are the only instruments capable of resolving both the temporal and spatial variability of surface currents in the coastal ocean, recent high-resolution views suggest that the coastal ocean is more complex than presently deployed radar systems are able to reveal. This work uses a hybrid system, having elements of both phased arrays and direction finding radars, to improve the azimuthal resolution of HF radars. Data from two radars deployed along the U.S. East Coast and configured as 8-antenna grid arrays were used to evaluate potential direction finding and signal, or emitter, detection methods. Direction finding methods such as maximum likelihood estimation generally performed better than the well-known multiple signal classification (MUSIC) method given identical emitter detection methods. However, accurately estimating the number of emitters present in HF radar observations is a challenge. As MUSIC’s direction-of-arrival (DOA) function permits simple empirical tests that dramatically aid the detection process, MUSIC was found to be the superior method in this study. The 8-antenna arrays were able to provide more accurate estimates of MUSIC’s noise subspace than typical 3-antenna systems, eliminating the need for a series of empirical parameters to control MUSIC’s performance. Code developed for this research has been made available in an online repository.