Computer models for underwater sound propagation

The state of affairs of computer models for underwater sound propagation loss estimation is discussed from the viewpoints of two segments of the sonar community, i.e., (1) those who develop the models and are primarily concerned with the accuracy of the estimations and (2) those who use such models and view propagation loss as only one of many areas in which sub-models are required. A list of propagation models, classified according to the analytical methods used in their derivations, is presented. The features and shortcomings of each class are then discussed in broad terms. Various sonar applications for which knowledge of propagation loss is needed are briefly delineated to indicate their diversity. Finally, various aspects of model assessment are addressed and a method for the quantitative assessment of comparative model accuracy (now in formative stages of development) is presented.