The inverse problem in hard acoustic scattering

The inverse problem considered is that of determining the shape of an acoustically hard obstacle in R 3 from a knowledge of the time-harmonic incident plane wave and the far-field pattern of the scattered wave. To solve this inverse Neumann problem in acoustic scattering without requiring the solution of integral equations, the authors have introduced a parametric representation in which the parameters are determined by a method of optimisation. Direct scattering can also be handled by this technique. Comparisons reveal that results are obtained quite simply and are just as accurate as those from other methods.