起伏地表的单程波动方程地震叠前正演

对于起伏地表条件下的地震叠前正演，射线追踪法可以灵活地处理起伏的地表条件，但是只包含了波的运动学特征，而且对复杂构造会出现盲区；而全程波动方程法，不仅计算效率低，而且正演记录的信噪比低。基于等时叠加原理和数学检波器的工作原理，灵活地将炮点和检波点布置于地表或地下的任何位置，提出了一种新的适用于起伏地表的单程波动方程地震叠前正演方法。该方法可以根据地质构造的复杂性，灵活地选取各种单程波场延拓算子进行计算，具有很强的适用性。两组数值模拟实验的结果表明该方法不仅具有很快的计算速度，而且可以获得没有直达波、多次波和其他干扰的高信噪比的共炮点叠前地震记录。此外，该方法不仅在理论上进一步推进了波动方程叠前正演的发展，而且具有很强的实际应用价值。

SEISMIC PRE-STACK FORWARD MODELING WITH ONE-WAY WAVE EQUATION UNDER RUGGED SURFACE CONDITIONS

For seismic pre-stack forward modeling under rugged surface conditions, ray-tracing method can flexibly handle the rugged surface conditions, but it can only reflect the kinematical features of waves and blind areas might appear when the structures are complex. While the full wave equation method is low in both computational efficiency and S/N ratio. Based on the principles of equitime stack and mathematical geophone, the shotpoints and geophones can be flexibly arranged on the surface or underground. A new seismic pre-stack forward modeling method with one-way wave equation suitable for use under rugged surface conditions is presented. It can flexibly select continuation operators of various one-way wave fields for computation according to the complexity of geologic structures, thus it has strong applicability. Simulation experiment results with two data sets show that this method not only has very high computation speed, but also can obtain high S/N common-source point pre-stack seismic records without direct waves, multiples and other interference waves. It further promotes the development of pre-stack forward modeling theory, and also has a high value of practical application.