Methods and applications of time–frequency analysis

Abstract

Time–frequency analysis is a common technique for studying signals whose spectral characteristics change over time, the principal method being the short-time Fourier transform or spectrogram. In the past decade, the theory and methods of time–frequency analysis have witnessed extensive development and application, due to the effective use of Cohen’s general formulation for time–frequency distributions. These methods have been found to be useful in a variety of areas, including acoustic scattering, biological signal analysis, and machine vibration analysis, among many others. A key development has been an understanding of the conditional moments of the distribution and their link to physical attributes of the signal such as its amplitude and phase. A review of the theory and methods of time–frequency analysis is presented, with an emphasis on applications in a variety of areas. [Work supported by ONR N00014-98-1-0680.]