A fast algorithm for the computation of incoherent propagation loss for variable water depth : A validation study

Accurate and fast estimation of propagation loss (PL) is needed for simulations of sonar or acoustic communication performance, and for environmental risk assessment. Accurate calculation of PL in range dependent and lossy waveguides can require computationally expensive wave theory techniques . In this work, a new propagation model is introduced for a range-dependent isovelocity waveguide. The proposed model is based on a combination of Weston’s average intensity approach and adiabatic normal mode theory. Thus, mode effects arising at both low frequencies and long ranges are automatically considered. Using this approach, the depth and frequency dependence of PL can be calculated analytically in terms of the Faddeeva function without tracing rays or calculating normal mode eigenvalues (except low order modes). For the validation, PL results are compared with KrakenC and Bellhop by using test cases from Weston Memorial Workshop 2010. Comparison with results computed independently using a full wave model demonstrate the accuracy of the model applied to WMW 2010. Thus, the proposed solution can be an alternative solution for large scale problems such as broadband calculations in sound mapping without requiring long computational times