Houston, TX 77005
2:00 p.m. Monday, Dec. 10, 2012
On Campus | Alumni
Applying the Born Approximation, which assumes single scattering, allows us to express the scattering potential of a region of interest as a Generalised Radon Tranform inversion, which we consider here in three dimensions and from a teleseismic perspective. The required approximations of traveltimes, amplitudes, gradient traveltimes and imaging scaling factors are found using finite difference calculations, including a new approach for amplitudes wherein the areas inside the ray tube at the source and receiver are approximated by applying Heron’s formula and a projection of the surface grid square onto the isochronal surface respectively. The problem is implemented in C and run in parallel with the Message Passing Interface protocol, with almost linear speedup for the S wavefield calculations. Results show that we are able to recover three dimensional structures well, with only significant velocity discontinuities causing problems.