  In sequel to Moradi et al. [2009, ApJ, 690, L72], we employ two established
numerical forward models (a 3D ideal MHD solver and MHD ray theory) in
conjunction with time-distance helioseismology to probe the lateral extent of
wave-speed perturbations produced in regions of strong, near-surface magnetic
fields. We continue our comparisons of forward modeling approaches by extending
our previous surface-focused travel-time measurements with a common midpoint
deep-focusing scheme that avoids the use of oscillation signals within the
sunspot region. The idea is to also test MHD ray theory for possible
application in future inverse methods.
