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本文首先把声波方程分解为两个分别适用于做正演和偏移的单向旁轴方程，然后用适合于做正演的单向方程来合成共炮记录。通过公式推导，提出合成共炮记录的时间一致性原理和两个过程──正过程和逆过程，即对于简单的水平各向同性层状介质，仅用正过程就能精确地合成共地记录；而对于复杂介质，则需借鉴射线法两点问题和波动方程共炮记录叠前深度偏移原理，给定炮点和检波点，在时间一致性原理的基础上，应用道过程方法，以单向声波方程分别正向延拓震源波场和反向延拓检波器波场，然后按记录适合成共炮记录。并且，还能将其演变为共炮记录叠前深度偏移法、零偏移距正演模拟法以及叠后深度偏移法。数值仿真试验结果表明，本文提出的各种方法均达到了预期的效果。
In this paper, the acoustic wave equation is first decomposed into two unidirectional paraxial equations that are suitable for forward and offset, respectively, and then synthesized with a one-way equation suitable for forward modeling. Through the derivation of the formula, the time consistency principle and two processes of synthesizing a common record are put forward: the positive process and the reverse process. That is, for a simple horizontal isotropic layered medium, the colinear recording For complex media, we need to draw on the two points of ray method and wave equation to record the principle of pre-stack depth migration. Given the time and consistency, we apply the method of channel process The unidirectional acoustic wave equations extend the source wavefield and the backward continuation wavefield in the positive direction, respectively, and then record them into suitable common records. And, it can be evolved into a common record of prestack depth migration method, zero offset forward modeling and poststack depth migration method. The numerical simulation results show that the proposed methods have achieved the expected results.