Open AccessAnalysis of Abnormal Wave Records by the Hilbert–Huang Transform Method
Author(s) -
Albena Veltcheva,
C. Guedes Soares
Publication year - 2007
Publication title -
journal of atmospheric and oceanic technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.774
H-Index - 124
eISSN - 1520-0426
pISSN - 0739-0572
DOI - 10.1175/jtech2067.1
Subject(s) - hilbert–huang transform , hilbert spectral analysis , hilbert transform , physics , instantaneous phase , amplitude , mode (computer interface) , acoustics , mathematical analysis , mathematics , optics , spectral density , computer science , telecommunications , statistics , energy (signal processing) , radar , quantum mechanics , operating system
The Hilbert–Huang transform method is used in this work to analyze wave records from the North Sea, which include abnormal waves. The analysis of the characteristics of abnormal waves is based on the local decomposition of wave data by using the intrinsic mode functions. The variations of amplitude of intrinsic mode functions around the time of the occurrence of abnormal waves are examined in order to investigate the contribution of different intrinsic mode functions on the abnormal waves’ profile, in an attempt to find relationships between them. The changes of local frequency of each intrinsic mode function in the vicinity of abnormal waves are examined. The essential nonlinearity of abnormal waves is considered as intrawave frequency modulation, a variation of the instantaneous frequency within one oscillation cycle. The Hilbert spectrum is used as a detector of abnormal waves.