Rossi Giovanni Battista, Crenna Francesco, Berardengo Marta, Piscopo Vincenzo, Scamardella Antonio
Department of Mechanical, Energy, Management and Transportation Engineering, University of Genova, Via Opera Pia 15A, 16145 Genova, Italy.
Department of Science and Technology, University of Naples "Parthenope", Centro Direzionale Isola C4, 80143 Naples, Italy.
Sensors (Basel). 2021 Apr 24;21(9):2995. doi: 10.3390/s21092995.
The reliable monitoring of sea state parameters is a key factor for weather forecasting, as well as for ensuring the safety and navigation of ships. In the current analysis, two spectrum estimation techniques, based on the Welch and Thomson methods, were applied to a set of random wave signals generated from a theoretical wave spectrum obtained by combining wind sea and swell components with the same prevailing direction but different combinations of significant wave heights, peak periods, and peak enhancement factors. A wide benchmark study was performed to systematically apply and compare the two spectrum estimation methods. In this respect, different combinations of wind sea spectra, corresponding to four grades of the Douglas Scale, were combined with three swell spectra corresponding to different swell categories. The main aim of the benchmark study was to systematically investigate the effectiveness of the Welch and Thomson methods in terms of spectrum restitution and the assessment of sea state parameters. The spectrum estimation methods were applied to random wave signals with different durations, namely 600 s (short) and 3600 s (long), to investigate how the record length affected the assembled sea state parameters, which, in turn, were assessed by the nonlinear least square method. Finally, based on the main outcomes of the benchmark study, some suggestions are provided to select the most suitable spectrum reconstruction method and increase the effectiveness of the assembled sea state parameters.
可靠地监测海况参数是天气预报以及确保船舶安全航行的关键因素。在当前分析中，基于韦尔奇（Welch）方法和汤姆森（Thomson）方法的两种谱估计技术，被应用于一组由理论波谱生成的随机波信号，该理论波谱是通过将风浪和涌浪分量相结合得到的，它们具有相同的主方向，但有效波高、峰值周期和峰值增强因子的组合不同。进行了一项广泛的基准研究，以系统地应用和比较这两种谱估计方法。在这方面，对应于道格拉斯量表四个等级的不同风浪谱组合，与对应于不同涌浪类别的三种涌浪谱相结合。基准研究的主要目的是系统地研究韦尔奇方法和汤姆森方法在谱恢复以及海况参数评估方面的有效性。将谱估计方法应用于不同持续时间的随机波信号，即600秒（短）和3600秒（长），以研究记录长度如何影响组合的海况参数，而这些参数又通过非线性最小二乘法进行评估。最后，基于基准研究的主要结果，提供了一些建议，以选择最合适的谱重建方法并提高组合海况参数的有效性。
