Spectral Estimation of Noisy Seismogram using Time-Frequency Analyses

Time-Frequency Analysis (Tfa) Techniques

Signal processing techniques are classified as time domain, frequency domain, and time-frequency domain methods. These methods are complementary to each other and selection of suitable technique for specific objectives in observational seismology becomes a challenging task. Therefore, some of the widely used time-frequency domain signals processing techniques have been revisited with respect to seismic signal processing needs and are discussed in this paper to find out their suitability in specific cases. Moreover, time-frequency analysis can give interesting information with regards to energy distribution over frequency bands. A number of techniques of time-frequency analysis, such as the Short Time Fourier Transform, Wavelet Transforms, and Wigner-Ville Distribution have been used for frequency estimation in non-stationary seismic signals obtained from an active seismic region in Himalayas through deployment of short network of short period seismographs.