On ray trajectories and pathtimes for acoustic propagation in a medium with velocity gradients

The author presents expressions for paths and pathtimes of rays in volume cells of the medium for which the sound velocity can be characterized in terms of a point velocity and a constant velocity gradient. Such parametrization permits the use of relatively large cells in the segmentation of the medium, so that the dimensional complexity of the tomographic formulation and inversion is reduced significantly. With a small number of segmentwise ramping vertical velocities, including velocity reversals, the profile parametrization allows the computational determination of arrival point targeted eigenrays from a given source point to a specified arrival point