Coherent effects of flow- and pressure-hull of a generic submarine on target scattering in an active sonar performance model

Abstract

Since the late eighties the sonar performance model ALMOST for active and passive sonar is under development at TNO. For active detection performance, first a point target was used, with a single target strength value dependent on parameters like aspect angle, based on measurements or other sources. However by now there is a demand for TS of ships and wakes with realistic dimensions and characteristics. A generic sub was modeled with additional software routines, as a pixel file. A newly developed time domain model for hull reflection was implemented, also using scattering pixels, assuming multiple scattering with damping in the metal hull layer. This extension of the pixel modelling is evaluated versus literature data. Some modeling results of target strength computations are shown, for a generic submarine with pressure hull, with aspect angle, frequency and bandwidth as parameters.