波动方程频率域偏移方法技术——分裂相移法

TECHNIQUE OF WAVE EQUATION MIGRATION IN FREQUENCY DOMAIN WITH “SPLIT PHASE-SHIFT”

本文介绍了分裂相移法频域偏移技术的基本原理,从运算可实现角度对为什么要另设一参考速度V₀作了解释.文章认为,在时间伸展变换的情况下,频散方程将不是一个圆,而是一个椭圆.对精确偏移公式与二阶近似偏移公式都进行了试验,并对存在横向速度变化情况下的偏移进行了初步尝试.地震模型的处理实例都附有与时域差分法偏移效果进行对比的图件,从而阐明该方法的优越性.

This paper deals with the technique of wave equation migration in frequency domain with "Split Phase-Shift", Also, why another reference velocity V0 should be given is explained from the viewpoint of operational feasibility. It is deemed that with the variation of time extension, the dispersion equation should be an ellipse rather than a circle. What's more, both the precision migration formulae and approximate migration formulae of second order were tested respectively. The first try on migration was made provided that the lateral velocity varies. All charts and drawings related for comparing with the migration result of time domain difference are attached to the seismic model examples processed so that the advantage of this method can be much more clearly reflected.