Autocorrelation Processing in Convergence Zones

摘要

This document contains the slide presentation entitled Autocorrelation Processing in Convergence Zones given at the 109th meeting of the Acoustical Society of America, 8-12 April 1985, in Austin, Texas. The sensitivity of first and second convergence zone arrivals to small changes in source location has been examined using two simple analytic models and the NUSC Generic Sonar Model (GSM). All three models indicate that the number of arrivals and the interpath time differences vary greatly with the location of the source in a convergence zone. For single point of inflection sound speed profiles, results obtained using the GSM show arrivals range from 1 to 10 in the first convergence zone and 1 to 11 in the second convergence zone. Travel time differences vary from less than one millisecond to several hundred, and these time differences cluster in well-defined groups. Analysis of GSM-produced autocorrelograms show several interpath time differences may occur within a millisecond of each other, requiring received signal bandwidths of several kilohertz to resolve individual correlogram peaks.