S U M M A R Y Recent studies show that the frequency content of continuous passive recordings contains useful information for the study of hydraulic fracturing experiments as well as longstanding applications in volcano and global seismology. The short-time Fourier transform (STFT) is usually used to obtain the time–frequency representation of a seismic trace. Yet, this transform has two main d...

To address the problem that dynamic wind turbine clutter (WTC) significantly degrades performance of weather radar, a WTC mitigation algorithm using morphological component analysis (MCA) with group sparsity is studied in this paper. The ground suppressed firstly to reduce compositions radar echo. After that, MCA applied and window used short-time Fourier transform (STFT) optimized lessen spect...

Spectral decomposition is an important tool for analysis of seismic data.This paper deals with the time-frequency analysis of non-stationary signals.Time-frequency method is a primary tool to analyze the evolving spectra of non-stationary signals. Short Time Fourier Transform (STFT) is a fundamental time-frequency method which reveals the frequency contents of the signal at each time point. The...

One of the most promising non-invasive markers of the activity of the autonomic nervous system is Heart Rate Variability (HRV). HRV analysis toolkits often provide spectral analysis techniques using the Fourier transform, which assumes that the heart rate series is stationary. To overcome this issue, the Short Time Fourier Transform is often used (STFT). However, the wavelet transform is though...

Introduction: Time-frequency representations (TFRs) indicate variations of the signal spectral characteristics with time, and they are the natural choice as an analysis tool for the non-stationary signals [1]. The main objectives of the various types of time-frequency distribution functions (e.g. Wigner-Ville distribution (WVD) [1], short-time Fourier transform (STFT) [1], the S-transform [2]) ...

Due to instability and poor identification ability of single pyroelectric infrared (PIR) detector for human target identification, this paper proposes a new approach to fuse the information collected from multiple PIR sensors for human identification. Firstly, Fast Fourier Transform (FFT), Short Time Fourier Transform (STFT), Wavelet Transform (WT) and Wavelet Packet Transform (WPT) are adopted...

Wavelet mathematical transformation and heart sound signal processing have recently been attracting a significant amount of attention in the research community. Why is this new priority being given to improved approach to heart sound signal analysis for accurate pattern recognition using the wavelet transform technique? This article provides an overview of this emerging field of digital bio-sig...

Magnetoencephalography (MEG) has a high temporal resolution well-suited for studying perceptual learning. However, to identify where learning happens in the brain, one needs to apply source localization techniques to project MEG sensor data into brain space. Previous source localization methods, such as the short-time Fourier transform (STFT) method by Gramfort et al.([6]) produced intriguing r...

Ground penetrating radar (GPR) was used to characterize the frequency-dependent dielectric relaxation phenomena in ordinary Portland cement (OPC) hydration in concrete changing from fresh to hardened state. The study was experimented by measuring the changes of GPR A-scan waveforms over a period of 90 days, and processed the waveforms with short-time Fourier transform (STFT) in joint time-frequ...

When the short-time Fourier transform (STFT) of an audio signal is arbitrarily modified, it no longer truly represents a time-domain signal. Classically, the accepted solution to obtain a time-domain signal from a modified STFT (MSTFT) is to invert the MSTFT to a time-domain signal that has an STFT that is closest to the MSTFT in a least squares sense. This is also the approach currently taken ...