Applications of the short time fourier transform (STFT) to seismic reflection data

The Short Time Fourier Transform (STFT) method allows the obtaining of time-frequency (t, f) images of seismic data, enabling many processes to be performed in this environment. In this study, the use of the STFT method in filtering seismic data, improving the resolution of seismic data, and qualitatively estimating the thickness and velocity structure of the layered earth model from seismic data is investigated. The effectiveness of the window function length (t, f) on the time and frequency resolutions of the images was tested in the STFT application. Short and long windows respectively provided temporal and frequency resolution. The diversity and practicality of STFT filtering in both time and frequency dimensions are demonstrated on synthetic and field data. By combining STFT with the Cepstrum technique (STFT-C), the vertical resolution of seismic data is effectively improved by attenuating the side lobes of seismic reflection wavelets and narrowing the main lobe, thus extending the available spectral band of the data into the low and high frequency region. Thus, thin layers and small-scale reflections can be imaged. The contribution of STFT to qualitatively estimating layer velocities and thicknesses along the depth in layered sedimentary environments is demonstrated with applications to synthetic and field data. As a result, it is seen that the STFT method provides many application possibilities and convenience in the processing of seismic data and is an effective method especially in increasing the vertical resolution of seismic data and estimating the layer model.