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地下细密分层引起地震反射资料视振幅随角度的变化(AVA)。反射的视AVA效应与传播的视AVA效应的区别在于:薄层组的反射同与基于角度的子波干涉有关;通过薄层介质的波的传播同基于角度的子波频散有关。显然以上两种视AVA效应都隐藏于视AVA对介质弹性参数的反演中。由于地震数据带宽的限制,与反射有关的于涉效应不能被消除。但在与角度有关的偏移方法成像过程中,可运用基于角度的滤波对整个传播角度进行均衡。假设源函数已知,且源的方向效应在偏移前得到补偿。与传播有关的频散效应可通过运用向下外推法中的广义逆一次波传播算子得以补偿。包括上述改进的基于角度的偏移可产生一个与角度有关且薄层视AVA效应被压制的反射率剖面。
Seismic reflection caused by the finely stratified underground layer varies with the angle (AVA). The difference between the apparent AVA effect of reflection and the apparent AVA effect of propagation is that the reflection of the thin layer group is related to the angle-based wavelet interference; the propagation of the wave through the thin-layer medium is related to the angle-based dispersion of the wavelet. Obviously the above two kinds of AVA effects are hidden in the visual AVA inversion of the elastic medium parameters. Due to the limitation of the seismic data bandwidth, the reflection related effects can not be eliminated. However, in angle-dependent migration method imaging, angle-based filtering can be used to equalize the entire propagation angle. The source function is assumed to be known, and the source directional effects are compensated before the offset. Dispersion effects related to propagation can be compensated by using the generalized inverse primary propagator in the downward extrapolation method. The angle-based offset, including the above improvements, can result in an angle-dependent reflectivity profile in which the thin-layer AVA effect is suppressed.