基于Malvar窗时频谱的反Q滤波方法

Seismic Inverse Q Filtering Using Malvar Window Based Time-Frequency Analysis

基于非弹性介质衰减模型,将衰减和频散表示为振幅和相位的算子,把补偿看成带衰减传播的逆传播过程,理论计算得到补偿需要的反算子。通过构造满足Malvar小波条件下的时窗,得到符合信号特征的时间频率谱,再利用最小二乘方法计算品质因子Q值,得到振幅和相位补偿需要的反算子,作用于时频谱,达到补偿的目的。数值试验结果显示,利用时频变换计算得到的Q值与先前设定Q值基本相符,反Q滤波补偿后的信号与无衰减信号对比,振幅和相位都得到很好的恢复。

A new inverse Q filtering method based on the time-frequency analysis using Malvar wavelet decomposition is proposed.Firstly,the forward phase and amplitude propagator based on mathematical model in anelastic model are computed.Then the composition process is considered as an inverse propagator.The operator is the function of Q,frequency,and travel time,through the frequency-time analysis based on Malvar wavelet decomposition.The proposed method is used to compensate the synthetic seismic trace produced by boundary element method.The result shows that it can correct amplitude attenuation and phase distortion effectively and stably.