Time-frequency representations have been of great interest in the analysis and classification of non-stationary signals. The use of highly selective transformation techniques is a valuable tool for obtaining accurate information for studies of this type. The Wigner-Ville distribution has high time and frequency selectivity in addition to meeting some interesting mathematical properties. However...

The 2D Quaternionic Fourier Transform (QFT), applied to a real 2D image, produces an invertible quaternionic spectrum. If we conserve uniquely the first quadrant of this spectrum, it is possible, after inverse transformation, to obtain, not the original image, but a 2D quaternion image, which generalize in 2D the classical notion of 1D analytical image. From this quaternion image, we compute th...

The structure is said to be damaged if there a permanent shift in the post-event natural frequency of as compared with pre-event frequency. To assess damage structure, time-frequency approach that can capture and required. In this study, determine these frequencies, local maximum synchrosqueezing transform (LMSST) method employed. Through simulation results, we have shown traditional methods su...

Using ESM, RWR and ARM missiles pose significant limitations to the performance of the radar systems in new battles. In these wars, MTI radars are commonly used with high Power to achieve long ranges, therefore they are easily detectable by the enemy EW receivers, and so they lose their effectiveness. In addition to having the ability of anti-Jamming and good ECCM, the radar systems should to u...

Abstmct-The Wigner-Ville spectrum has been recently introduced as the unique generalized spectrum for time-varying spectral analysis. Its properties are revised with emphasis on its central role in the analysis of second-order properties of nonstationary random signals. We propose here a general class of spectral estimators of the Wigner-Ville spectrum: this class is based on arbitrarily weight...

This correspondence presents an iterative instantaneous frequency (IF) estimation scheme in which successive IF estimates are obtained from the peak of the cross Wigner-Ville distribution (XWVD) using a reference signal synthesized from an initial IF estimate. Theoretical and practical aspects of performance are discussed, and compared with other methods.

The measurement algorithms applied in power quality measurement systems are based on Fast Fourier Transformation. That one-dimension frequency analysis is sufficient in many cases. However, to illustrate the character of the signal in a more comprehensive manner, it is crucial to represent the investigated signal on time-frequency plane. There are a lot of time-frequency representations (TFR) f...