Evaluation of Alternative Direction-of-Arrival Methods for Oceanographic HF Radars
Evaluation of Alternative Direction-of-Arrival Methods for Oceanographic HF Radars
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DOI：
10.1109/joe.2019.2914537
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发表时间：
2020-07
影响因子：
4.1
通讯作者：
B. Emery
中科院分区：
文献类型：
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作者：
B. Emery
大多数海流测量高频雷达通过多信号分类 (MUSIC) 算法获取从海洋反向散射的信号的到达方向 (DOA)。这些雷达通常在低信噪比 (SNR)、低数据样本（又称快照）数量以及信号源数量接近或超过接收天线元件数量的条件下运行。在这些情况下提高雷达数据的准确性和覆盖范围将改善美国综合海洋观测系统等雷达网络产生的数据，揭示对沿海海洋动力学的新认识。本文对过去 10-20 年开发的 DOA 技术进行了评估，该技术使用基于仿真的方法应用于海洋高频雷达。使用三种常用接收阵列进行的模拟表明，使用交替投影最大似然估计 (MLE-AP) 可以获得相似的精度，并且由于与 MUSIC 相比获得的 DOA 解的数量较多，因此覆盖范围有所改善。这些进步带来了更高的计算成本，尽管差异是可以控制的。该分析还说明需要识别和评估与 MLE-AP 结合使用的信号检测方法（即识别同时源方位数量的方法）。总体而言，这些结果表明高频雷达生成的洋流地图的数据覆盖范围有所改善，从而改善了使用它们的许多实际应用，例如溢油响应、搜索和救援。
The majority of ocean current measuring HF radars obtain the direction of arrival (DOA) of signals backscattered from the ocean with the multiple signal classification (MUSIC) algorithm. These radars often operate under conditions including low signal-to-noise ratio (SNR), low numbers of data samples (aka snapshots), and with the number of signal sources approaching or exceeding the number of receive antenna elements. Improving the accuracy and coverage of the radar data in these situations would improve data produced by radar networks such as the U.S. Integrated Ocean Observing System, revealing new understanding of coastal ocean dynamics. This paper presents an evaluation of DOA techniques developed over the last 10–20 years, for application to oceanographic HF radars using a simulation-based approach. Simulations performed using three commonly used receive arrays suggest that the use of maximum-likelihood estimation by alternating projection (MLE-AP) leads to similar accuracy, with improvement in coverage due to the higher number of DOA solutions obtained when compared to MUSIC. These advances come at a higher computational cost, though the difference is manageable. The analysis also illustrates the need to identify and evaluate signal detection methods (i.e., methods to identify the number of simultaneous source bearings) to work in conjunction with MLE-AP. Overall, these results suggest improvements in the data coverage of ocean current maps produced by HF radars, and thus in the many practical applications employing them such as spill response, and search and rescue.