2025_programme: Acoustic Backscattering from Complex Objects

• Day: June 16, Monday
    Location / Time: D. CHLOE at 12:20-12:40
• Last minutes changes: Cancelled.
• Session: 17. Target Echo Strength – Measurements and Modelling
  Organiser(s): David Nunn 
  Chairperson(s): David Nunn 
• Lecture: Acoustic Backscattering from Complex Objects [Invited]
  Paper ID: 2214
  Author(s): Iris Roger-Eitan, Evgeny Chernokozhin, Anna Gleizer, Arne Stoltenberg, Ingo Schaefer, Amir Boag
  Presenter: Iris Roger-Eitan
  Abstract: Understanding sound scattering from complex targets is crucially important in many underwater applications. Such targets, containing several scattering centers, can exhibit multiple scattering phenomena, making both measurements and computational studies challenging.\nOur recent work included studying scattering by complex objects such as the Icosahedron, a regular polyhedron consisting of twenty trihedral corner reflectors. Numerical computations for such a complex target may be demanding in terms of storage and computational time. We aimed to determine whether simple computational methods capture the scattering features with sufficient accuracy over the frequency bands of interest.\nExperimental studies of such complex scatterers also present various challenges. For example, when far field measurements are desirable, but not possible due to the size limitations. When targets are complex, single, double or multiple scattering each with a defined phase and interferences may occur, each contributing to the overall target echo strength (TES). Multiple scattering is not well suited for imaging and near-field to far-field algorithms. Moreover, every scattering mechanism may have a different far field response. However, sometimes some lenient assumptions apply, for instance, if the interactions between the sub-scatterers are not prominent. In these cases, we may treat the target as a collection of individual non-interacting sub-scatterers or define an effective scatterer including a subset of the physical sub-scatterers. This representation results in a reduced far field complexity and a simpler overall description. Here, we aim to verify whether such an assumption is valid in our setup.\nBy validating, when possible simplified numerical methods are sufficiently accurate, and when lenient assumptions apply when analyzing measurement results, we seek to improve our understanding of scattering from complex targets and allow future studies to focus on the essential features of the scattering.\n
• Corresponding author: Ms Iris Roger-Eitan
  Affiliation: Rafael Advanced Defence Systems Ltd.
  Country: Israel