C-SNAP: Coupled SACLANTCEN Normal mode propagation loss model

Abstract

On the basis of a widely used and efficient range-independent normal mode code, SNAP, and a numerical solution technique for one-way mode coupling obtained from KRAKEN, we have built a range-dependent propagation loss model called C-SNAP. While the mathematical aspects of the problem have already been described in detail, here we present the implementation of the model and give a detailed discussion of the numerical considerations that are fundamental to its accurate and efficient use. Finally the use of the model is illustrated by a series of examples.