REVSPEC—A reverberation spectrum numerical model

Abstract

The REVSPEC model provides a numerical evaluation of the reverberation spectrum for a general set of sonar system parameters and environmental conditions. The model is a numerical evaluation scheme based on the discretization approach of Ackerman for a general formulation of reverberation as developed by Fauer, Ol'shevskii, and Middleton. The model produces surface, volume, and/or bottom reverberation spectra and power levels as functions of the sonar system (transmit signal waveform and power level, sampling rate, transmit/receive and horizontal/vertical beampatterns), environment (spreading and absorption propagation losses, backscattering strengths, wind speed and direction, scatterer motion), and sonar platform (motion, depth, direction). The reverberation spectra at the receiver input and at the receiver output for a range‐gated and waveform‐weighted receiver are generated. The reverberation is nonstationary in that the spectra vary with time (and range) both in their spectral shape and power levels. Intrinsic assumptions include: primary scattering only (no secondary scattering), isovelocity ocean (straight line propagation paths), direct path (no boundary forward reflections), quasistationary narrowband transmit signals, backscattering from a large number of randomly distributed, weak, discrete scatterers, and radial velocity distributions of boundary and volume scatterers are uniform in space. The model formulation is presented and examples which illustrate its applicability for sonar systems analysis are given.