Broad Band Acoustic Modeling of Reverberation for Torpedo Simulators

Testing and evaluation of torpedo active search and homing performance in reverberant environments is best done by high fidelity simulation. The Phase I part of the work being proposed here concluded that in order to provide high fidelity and computationally efficient broadband simulations of realistic reverberation, a new approach was required. Previous approaches were based on frequency domain-based spectral factorization, which could not easily be generalized to the broadband case and, at the same time, remain computationally feasible. This proposal describes a task with the goal of providing a time-domain based model of reverberation for torpedo simulators. It has the capability of providing a computationally feasible simulation that contains the broadband case in a natural manner. This means that the bandwidth and any associated Doppler shifts will be correctly modeled without any approximations, unlike the spectral factorization approaches. A further advantage is that, contrary to the spectral factorization approaches, this time-domain approach is not limited to quasi-stationarity and Gaussianity. The result will be a processor that can provide time series that faithfully and accurately represent the outputs of the individual hydrophones for a multi-beam torpedo sonar receiver.