一种地震子波峰值频率的估计方法

针对常规方法估计地震子波峰值频率的精度不高的问题，提出了一种估计地震子波峰值频率的特征结构（ES）法．该方法先对地震子波的自相关矩阵进行特征分解，再用最大特征值对应的特征向量逼近其峰值频率成分子空间，同时用其余特征向量逼近非峰值频率成分子空间，然后计算不同频率的正弦谐波在峰值频率成分子空间与非峰值频率成分子空间的投影系数之比，最后搜索最大比值对应的谐波频率即为检测到的地震子波峰值频率．与常规方法相比，ES法能更精确地检测地震子波的峰值频率．采用合成的零偏垂直地震剖面资料进行了仿真实验，结果表明，与快速傅里叶变换和Burg最大熵相比较，ES法检测到的品质因子精度高，方差约减少了43％，同时估计的峰值频率也更精确．

Estimating Method for Peak Frequencies of Seismic Wavelets

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%.