In
marine seismic exploration, OBC bin fold is impacted by the depth and velocity
of target layer, as well as the water depth and velocity, etc. Therefore, on
the basis of the Snell’s law, the authors derive a quartic equation of OBC reflection
point coordination of the model with two horizontal reflection interfaces. From
the quartic equation, accurate solutions of the reflection point are obtained
and determined analytically based on the different actual conditions, expressed
as a function of water velocity, water depth, offset, underwater target depth
and velocity at the reflection point. The new method is adaptive to the
variation of water depths and target-layer velocity and improves the
calculation efficiency and accuracy of OBC bin fold.