In the simulation of wave propagation phenomenon truncating the grid will lead to unacceptable reflection artifacts from boundary. One remedy is to extend simulation region by Perfectly Matched Layers (PML) that contains a special absorbing medium...

by the truncation, we derive a suitable Nearly Perfectly Matched Layers (NPML) boundary condition. In the numerical results proposed second-order TTI visco-acoustic wave equations are implemented and efficiency of derived NPML is investigated....