Fig. 4: The suppression of backscattering from a steel spherical shell in the Pekeris waveguide.

a The total fields induced by the prescribed incident fields for suppressing backscattering from the steel spherical shell at 215 Hz, with the scatterer placed at a horizontal distance of 500 m, 100 m, and 1000 m, respectively. b The prescribed incident wavefronts are a function of depth for the three scatterer positions. The left and right panels show the amplitude and phase, respectively.