Development of novel post processing algorithm for the enhancement of underwater sonar images for high resolution

Abstract

newlineThe subject of underwater acoustic modeling deals with the translation of our newlinephysical understanding of sound in the sea into mathematical formulas solvable by newlinecomputers. This thesis divides the subject of underwater acoustic modeling into three newlinefundamental aspects: the physical principles used to formulate underwater acoustic newlinemodels; the mathematical techniques used to translate these principles into computer newlinemodels; and modeling applications in sonar technology and oceanographic research. newlineThe material presented here emphasizes aspects of the ocean as an acoustic medium. newlineIt shows mathematicians and physical scientists how to use this information to model newlinethe behavior of sound in a spatially complex and temporally variable ocean. newlineRecent developments in underwater acoustic modeling have been influenced newlineby changes in global geopolitics. These changes are evidenced by strategic shifts in newlinemilitary priorities as well as by efforts to transfer defense technologies to non defense newlineapplications. The strategic shift in emphasis from deep-water to shallow-water naval newlineoperations has focused attention on improving sonar performance in coastal regions. newlineThese near-shore regions, which are sometimes referred to as the littoral zone, are newlinecharacterized by complicated and highly variable acoustic environments. Such newlinedifficult environments challenge the abilities of those sonar models intended for use in newlinedeep-water scenarios. This situation has prompted further development of underwater newlineacoustic models suitable for forecasting and analyzing sonar performance in newlineshallow-water areas. The policy of defense conversion has encouraged the transfer of newlinesonar modeling technology to non defense applications. Much of this transfer has newlinebenefited the growing field of environmental acoustics, which seeks to expand newlineexploration of the oceans through acoustic sensing. Such technology conversion is newlineexemplified by the utilization of naval underwater acoustic models as both prognostic newlineand diagnostic tools in sophisticated experiments employ