Tidal Analysis Using Time–Frequency Signal Processing and Information Clustering

Autor: Antonio M. Lopes, Jose A. Tenreiro Machado
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Entropy, Vol 19, Iss 8, p 390 (2017)
Druh dokumentu: article
ISSN: 1099-4300
DOI: 10.3390/e19080390
Popis: Geophysical time series have a complex nature that poses challenges to reaching assertive conclusions, and require advanced mathematical and computational tools to unravel embedded information. In this paper, time–frequency methods and hierarchical clustering (HC) techniques are combined for processing and visualizing tidal information. In a first phase, the raw data are pre-processed for estimating missing values and obtaining dimensionless reliable time series. In a second phase, the Jensen–Shannon divergence is adopted for measuring dissimilarities between data collected at several stations. The signals are compared in the frequency and time–frequency domains, and the HC is applied to visualize hidden relationships. In a third phase, the long-range behavior of tides is studied by means of power law functions. Numerical examples demonstrate the effectiveness of the approach when dealing with a large volume of real-world data.
Databáze: Directory of Open Access Journals