一种带限稳定的反Q滤波算法

反Q滤波是波传播的逆过程，可同时消除吸收和频散效应。Gabor域反Q滤波方法是以Gabor变换谱代替向下延拓的波场，在对二维时频谱进行稳定的反Q滤波处理后，再使用Gabor逆变换重建时间域地震道。相对于反Q滤波方法的分层实现，该算法可应用更精确的连续Q模型，且不需对二维振幅补偿算子进行近似，其计算效率更高，反Q滤波结果更准确。为了改善补偿效果且不放大环境噪声，在Gabor域反Q滤波过程中联合应用时变带通滤波器，该带通滤波器的高截频从某一时间处随旅行时沿双曲线轨迹变化，以适应衰减介质中信号带宽随旅行时的变化。理论数据测试和实际资料应用的结果均表明，联合时变带通滤波器的反Q滤波算法对含噪地震数据是稳健的，可在保持信噪比的同时提高地震资料的分辨率。

A band-limited and robust inverse Q filtering algorithm

Inverse Q filtering in Gabor domain makes use of Gabor spectrum instead of the downward wavefield. It performs stabilized inverse Q filtering in 2-D time-frequency spectrum, and reconstructs seismic traces in the time-domain. Compared with the layered implementation of inverse Q filtering, this algorithm may use a more accurate earth Q model without 2D amplitude compensation operator approximation. So its efficiency and accuracy are much higher. In order to improve the compensation effect without boosting the ambient noise, we perform inverse Q filtering in Gabor domain by incorporating a time-variant passband filter. The high-cut frequency of this passband filter follows a hyperbolic trajectory of a seismic signal travel time at a specified point as the signal bandwidth varies in media due to the attenuation. Test results on theoretical and real data demonstrate that the inverse Q filtering algorithm incorporating a time-variant passband filter is robust and effective for seismic noisy data, and improves seismic resolution with no S/N degradation.