This application note discusses the solution used for the detection of acoustic emissions of surface and underwater vessels by means of the “Autonomous Acoustic Measurement System” (Sistema Autonomo per Rilievi Acustici, SARA). Activities were carried out by the Italian Navy at the Naval Experimentation and Support Centre (Centro di Supporto e Sperimentazione Navale, CSSN) of La Spezia.
In order to examine the “acoustic fingerprint” of surface and underwater vessels, the Italian Marine conducts acoustic analysis of the noise detected by hydrophones. All tests are performed with the “Autonomous Acoustic Measurement System” (Sistema Autonomo per Rilievi Acustici, SARA) in accordance to international standards and specific require-ments of the Navy (STANAG 1136, ANSI/ASA S.12.64, etc.) in frequency bandwidths from 5 to 20,000 Hz.
The heart of the “SARA” is the imc C-SERIES measurement system, a standard solution used here to record acoustic signals, perform live processing and calculations of spectra and directly transmit the data in real time via radio link, to the naval units under test.