Ship acoustic signature measurements by using an AUV mounted vector sensor

This paper proposes a new approach to perform acoustic signature measurements of ships. An Autonomous Underwater Vehicle (AUV) fitted with an acoustic vector sensor is used for acoustic data collection. The purpose of this work is to identify acoustic noisy sources on board the ship being tested using a joint time-frequency domain algorithm based on the use of the Short-Time Fourier Transform. Acoustic data can also be used for bearing-only tracking of ships exploiting their radiated noise. An overview of acoustic signature processing is given, and significant details on the discrimination of different sources are explained. Data collection took place at sea in the gulf of La Spezia while the NATO Research Vessel Leonardo was operating as a vessel under test. The AUV mounted vector sensor has proven to be very effective in its ability to distinguish and track various components of the acoustic signature at low frequencies.