To test the resolution matrix estimation we inverted for a single output offset (225m) made from three data offsets (200, 225, and 250m). The Kirchhoff operator was a simple 2-D modeling operator and its adjoint using 2nd order, first-arrival eikonal traveltimes. For the synthetic case a smoothed version of the correct velocity model was used. The real data example uses a smoothed version of the SMART Ehinger and Lailly (1995); Jacobs et al. (1992) velocity model provided by Elf Aquitaine.