Resonance scattering studies in underwater acoustics: the direct and inverse problems

The problem involved in acoustical resonance scattering from axisymmetric targets is briefly reviewed, and four developments introduced recently in this field are presented. The first is the use of the group velocity of resonating surface waves. The second is a very fast method of resonance identification using wideband ultrasound (the pulsed resonance identification method). The third is an application of an artificial intelligence algorithm to the inverse problem, and the last is concerned with the use of parametric results to solve this very same problem