TITLE:
Harmonicity Spectrum
AUTHORS:
Lintao Liu, Guocheng Wang, Xiaoqing Su, Xuepeng Sun, Huiwen Hu, Xiaowen Luo
KEYWORDS:
Normal Time-Frequency Transform, Complex Correlation Coefficient, Harmonicity Spectrum, Weak Harmonic Signal Detection
JOURNAL NAME:
Open Journal of Statistics,
Vol.13 No.5,
October
30,
2023
ABSTRACT: Perceiving
harmonic information (especially weak harmonic information) in time series has important scientific and
engineering significance. Fourier spectrum and time-frequency spectrum
are commonly used tools for perceiving harmonic information, but they are often
ineffective in perceiving weak harmonic signals because they are based on
energy or amplitude analysis. Based on the
theory of Normal time-frequency transform (NTFT) and complex correlation
coefficient, a new type of spectrum, the Harmonicity Spectrum (HS), is
developed to perceive harmonic information in time series. HS is based
on the degree of signal harmony rather than energy or amplitude analysis, and
can therefore perceive very weak harmonic information in signals sensitively.
Simulation examples show that HS can detect harmonic information that cannot be detected by Fourier spectrum or
time-frequency spectrum. Acoustic data analysis shows that HS has better
resolution than traditional LOFAR spectrum.