In this example, I assume a line source generates plane waves with a incident angle of 30 degrees. I use the algorithm to trace the rays in a synthetic model. The results are displayed in Figure . Again, the raster images of the synthetic slowness model are overlain with the wavefronts and rays. The wavefronts are plotted at a constant time-interval. The rays are traced with the starting points distributed uniformly along the surface. The incident angles of the rays are equal to 30 degrees.