Time-frequency analysis has been found to be effective in monitoring the transient or timevarying characteristics of machinery vibration signals, and therefore its use in machine condition monitoring is increasing. This paper proposes the application of time-frequency methods, which can provide more information about a signal in time and in frequency and gives a better representation of the sig...

A new member of the Cohen’s class time-frequency distribution is proposed. The kernel function is determined adaptively based on the signal of interest. The kernel preserves the chirp-like components while removing interference terms generated due to the quadratic characteristic of Wigner-Ville distribution. This approach is based on the chirplet as an underlying model of biomedical signals. We...

Target identification using Inverse Synthetic Aperture Radar (ISAR) imaging is an important tool required with the current day high-resolution radars for threat assessment and evaluation. Identification of target using the ISAR images is gaining popularity because of its importance in decision-making. The ISAR image represents the target’s reflectivity measured at discrete frequencies in the RF...

This research paper presents some methods to assess the performance of Wigner Ville Distribution for Time-Frequency representation of non-stationary signals, in comparison with the other representations like STFT, Spectrogram etc. The simultaneous timefrequency resolution of WVD is one of the important properties which makes it preferable for analysis and detection of linear FM and transient si...

This paper is focused on the problem of mode identification of Lamb waves in ultrasonic testing, and the principle and process of two time-frequency transform method, smooth pseudo Wigner–Ville distribution and two-dimensional Fourier transform, were discussed. The experimental work were carried out in aluminium plates, and the single and multimode Lamb waves were excited by 5MHz oblique incide...

[1] Magnetospheric ultra-low-frequency (ULF) waves (f = 1 mHz to 1 Hz) exhibit highly time-dependent characteristics due to the dynamic properties of these waves and, for observations in space, the spacecraft motion. These time-dependent features may not be properly resolved by conventional Fourier techniques. In this study we examine how the Wigner-Ville distribution (WVD) can be used to analy...

A flexible system for timefrequency signal analysis is presented. It is based on the S-method, which has a significant advantage in implementation since it can involve, as a key intermediate step, the Shorttime Fourier transform or the Hartley transform, each widely studied and commonly used in practice. Signal invariant and signal dependent system forms are presented. Hardware design, for a fi...

We present a new method for time-frequency representation (TFR), which combines a Fourier Bessel (FB) series expansion and the Wigner-Ville distribution (WVD). The FB series decomposes a multi-component signal into a number of single component signals before the WVD is applied. and then WVD is applied on the single component signals to analyze its time-frequency distribution (TFD). The simulati...