A comparative analysis of side-looking sonars for rapid classification of underwater intruders

Abstract

One aspect of NURC's 2008 efforts in port protection involves building a prototype system for countering a subsurface threat. Such a capability against underwater intruders in ports requires surveillance of the underwater domain and the means for response when intruders are detected. Multiple exercises and trials in 2007 and 2008 have provided opportunities to experiment with different side-looking sonars for the reacquisition and classification of an underwater intruder. A response vessel carrying the classification sonar was provided an intercept vector from a wide-area surveillance sonar. Both manned and unmanned response surface response craft were used in the trials. The comparative results, analysis and implications for the sonars are reported here. Preliminary conclusions show the possibility to reacquire an underwater contact with ease, and classify a contact as a diver with varying levels of success. The analysis and reporting follows a methodology used in earlier trials at NURC. The parameters correlated with successful classifications are identified here. The relative performance of side-looking sonar compared to forward-looking sonar is considered.