Abstract
It is well known that the far field expansion provides a radiation wave function in terms of the inverse powers of the distance everywhere outside the scatterer, explicitly given in terms of the trace of the scattered wave upon a sphere adequately far from the scatterer. This very useful result is stated as the far field expansion theorem introduced by Atkinson and Wilcox in the middle of the last century.
In the present Phd research proposal, we investigate the applicability and effectiveness of this theorem in calculating the wave field scattered by a smooth enough starshaped scatterer, excited by an acoustic plane low frequency incident wave.
The calculation of the low frequency expansion of this field is feasible analytically only for scatterers with certain geometric shapes and for a limited number of its first terms. The information for the full expansion that is pursued in the present research, is useful both for solving the direct scattering problem, if the geometry of the scatterer does not allow for acquiring an analytical solution and for dealing with the inverse scattering problem where the knowledge of each additional term of the low frequency expansion provides valuable information about the geometry and physics of the unknown in this case scatterer..
Advisory Committee
Supervisor Kariotou Foteini, Assistant Professor, SST, HOU
Members: Hadjinicolaou Maria, Professor, SST, HOU
Tsitsas Nikolaos, Assistant Professor, Department of Informatics, Aristotle University of Thessaloniki