Abstract:
A novel formalism is proposed for the exact isolation of resonances from
scattered waves for acoustic wave scattering from elastic or liquid bodies. The
resonance scattering function (RSF) consisting of purely resonance information
is proposed. Both magnitudes and phases of isolated resonances can be correctly
obtained by using the proposed formalism while previous works based on the
conventional resonance scattering theory (RST) can produce only magnitude
correctly. The reason why previous works using RST could obtain correct
magnitude information of resonances for the case of acoustic wave scattering is
explained. Acoustic wave scattering from a variety of submerged bodies is
analyzed by utilizing the RSF and the isolated resonances were compared with
previously published studies. The exact (pi)-phase shift through resonances and
at the anti-resonances caused by the interaction between adjacent resonances,
which has never been obtained by using RST, shows that the proposed formalism
properly extracts the resonances from scattered waves. Due to the differences in
phases, the novel formalism and the conventional RST generate different
resonance spectrum. For elastic wave scattering, even magnitudes of resonances
isolated by the proposed formalism will be different from those obtained by the
conventional RST. [sup