An improved method for Q-factor estimates based on the frequency-weighted-exponential function

The frequency-weighted-exponential (FWE) function was designed to fit asymmetric amplitude spectra by two parameters: symmetry index and bandwidth factor. It was applied to Q-factor estimates by fitting the amplitude spectra of source and attenuated wavelet. This method for Q-factor estimates was called the FWE method. The accuracy of the Q-factor estimates by the FWE method depends on the similarity between the modeled FWE functions and the amplitude spectra of source and attenuated wavelet. However, the amplitude spectra of source and attenuated wavelet are poorly fitted when the FWE function are modeled by measuring the symmetry index and bandwidth factor by their definitions. Hence we perform an improvement to the FWE method, where two FWE functions are employed to fit the amplitude spectra of source and attenuated wavelet by the Least Square Method to obtain the optimal symmetry index and bandwidth factor. The improved FWE method enhances the accuracy of the Q-factor estimates, and it also maintains the advantages of good applicability and tolerance to random noise of the original FWE method.