“…Hence, this result provides practitioners with the needed confidence to employ the proposed boundary condition on artificial boundaries that are "close" to the considered scatterer's boundary, leading therefore to small computational domains. Note that the situation is not the same in the case of the standard DtN2/BGT2 boundary conditions (recall that in 3D, the standard DtN2 and BGT2 conditions coincide [11]). More specifically, in the high-frequency regime, the high-order spurious modes (whether they are propagating, evanescent, or grazing modes) created by the standard BGT2/DtN2 boundary condition do not decay, as observed in [2], requiring therefore to place the artificial boundary very far from the obstacle to avoid the deterioration of the accuracy level due to the possible contamination of these non physical modes.…”