An assessment of the variability of low-frequency active sonar performance in shallow water

Abstract

The performance of a generic low-frequency, active sonar was simulated using a broadband, coupled mode, propagation model. The low-frequency active system consisted of a 1000-Hz source with source level of 220 dB and a towed horizontal array of hydrophones. The ocean environment used in the simulation was 159 tomographic snapshots of the Barents Sea Polar Front, taken every 5 min. These tomographic images over a range of 35 km provide a virtual ocean in which system performance and environmental data requirements can be assessed. The probability of detection calculated as a function of time for 13 h is compared with that estimated using a range- and time-independent assumption. The importance of coastal acoustic tomography for tactical applications will be discussed.