Focusing on the problem that peak frequencies of seismic wavelets estimated by common methods are imprecise

an eigen-struct(ES)method for estimating peak frequencies of seismic wavelets is proposed

in which the self-correlation matrix of a seismic wavelet is eigen-decomposed firstly

and then the subspace of peak frequency component is approximated by the eigen-vector corresponding to the maximum eigen-value

the subspace of other frequency components is approximated by residual eigen-vectors

and the ratios of projected coefficients for different sine-waves on these two subspaces are computed

finally the harmonic frequency corresponding to maximum ratio is the peak frequency of the seismic wavelet. This method can give more precise peak frequency of a seismic wavelet than common methods. Simulation results of synthetic zero-offset vertical seismic profiles show that the precision of quality factors and peak frequencies estimated by ES method is higher than that of fast Fourier transform and Burg maximum entropy

and the variance of quality factors decreases by about 43%.