Introduction

Historically, sonar technologists initiated the development of underwater acoustic modeling to improve sonar system design and evaluation efforts, principally in support of naval operations. The wide breadth of material covered in precludes exhaustive discussions of all existing underwater acoustic models. The coupling of the two types of models provides a valuable set of prediction tools to naval force commanders by enabling them to respond to the changing environmental conditions that affect the sonar performance. The principal attributes that characterize operational oceanography are: routine and systematic measurements of the oceans and atmosphere; modeling, simulation, analysis, and interpretation of these measurements to generate useful information products; and rapid dissemination of these products to the user communities. Underwater acoustics entails the development and employment of acoustical methods to image underwater features, to communicate information via the oceanic waveguide, or to measure oceanic properties.