基于时频域谱模拟的时变子波估计方法

为解决地层衰减作用造成传统子波提取方法提取结果不准确的问题，提出了一种基于时频谱模拟的时变子波估计方法。首先对非平稳地震记录进行改进的广义S变换后再作时频滤波处理，然后采用谱模拟方法从处理后的地震记录时频谱中拟合出每一时刻的子波振幅谱，最后通过反傅里叶变换得到时域子波，从而实现时变子波的精确提取。与常规分段提取时变子波方法相比，该方法不需要子波分段平稳的假设，当相邻层段子波属性存在较大变化时也能准确估计出时变子波。理论分析和模型试算结果表明，该方法在提取时变子波并用于提高地震资料分辨率方面具有一定的可行性和有效性。

To solve the problem that the seismic wavelet estimated by conventional methods is inaccurate because of the effect of earth-attenuation,a time-variant seismic wavelet estimation method based on spectral modeling in time-frequency domain is proposed.At first,the non-stationary seismic record is transformed by the improved generalized S-transformation and followed by time-frequency filtering processing.And then the wavelet amplitude spectrum for each moment is fitted from the time-frequency spectrum of processed seismic record using spectral modeling method.Finally,after inverse Fourier transformation,the time-variant wavelet is achieved with high accuracy.Compared with conventional segmented extracting methods of time-variant wavelet,the proposed method can be also used to estimate time-variant wavelet accurately when the seismic wavelet properties varied obviously in adjacent stratum.Theoretical analysis and simulation results show that the method is feasible and effective in extracting time-varying wavelet and improving the resolution of seismic data.