Numerical analysis of the finite-offset common-reflection-surface traveltime approximations

► The finite-offset (FO) common-reflection-surface (CRS) depends on five parameters. ► We obtain a new four-parameter approximation for diffractions from the CRS formula. ► Both approximations compare well with the traveltimes of the ray tracing modeling. ► Decreasing number of parameters will decrease the computational efforts for stacking. ► We determine the priority for searching for the five parameters of the FO CRS stack.