Finite difference traveltime calculation for head waves travelling along an irregular interface

Abstract

Some special operators and algorithms have been introduced to the finite difference (FD) traveltime calculation to overcome numerical instability related to head waves. However, further modifications are still required for head waves travelling along an irregular interface, because the interface often generates multiple arrivals of the head waves, causing another instability in the traveltime calculation. We solve this multipathing problem by defining new 3-D operators and implementing them with illumination conditions. Podvin & Lecomte operators are adopted for 2-D models. We then apply these operators to 2- or 3-D synclinal structures for checking their feasibility.