About the boundary condition approximation in the higher-order grid-characteristic schemes

In this paper, we consider the problem of constructing a numerical solution to the system of equations of an acoustic medium in a fixed domain with a boundary. Physically, it corresponds to the process of the seismic wave propagation in geological media during the procedure of the seismic exploration of hydrocarbon deposits. The system of partial differential equations under consideration is hyperbolic. To construct its numerical solution, a grid-characteristic method is used on an extended spatial stencil. This approach makes it possible to construct a higher-order approximation scheme at the internal points of the computational domain. However, it requires a careful construction of the numerical solution near the boundaries. In this paper, the approach that preserves the increased approximation order up to the boundary is proposed. The verification numerical simulations were carried out.