On the use of an absorption layer for the angular spectrum approach (L).

Reducing the spatial aliasing error of the angular spectrum method by using an absorption layer is investigated in this paper. The acoustic equation including the absorption layer is presented and is transformed in the spatial frequency domain, where an implicit analytic solution is readily available. Its approximation, which is more suitable for numerical simulation, is derived and is numerically implemented. The comparisons between the present method and available methods demonstrate its validity and advantages.