Aspect-dependent acoustic characterization of an underway autonomous underwater vehicle

Acoustic emissions emitted by an underway REMUS-100 autonomous underwater vehicle (AUVs) are analyzed with array beamforming. Characterizing emissions of underway AUVs is challenging due to a variety of factors such as low source levels of some vehicle types, continually varying propagation conditions, and inherent uncertainties in vehicle location. While aspect-dependent spectral and source level emissions are available for a wide range of surface craft types, few articles have analyzed these for underway AUVs. Array beamforming is a known method of increasing gain of a weak signal in the presence of interference and noise, and propagation modeling tools can provide estimates of transmission loss between a source and receiver. These techniques are used to measure the aspect-dependent source level and spectral content from the propulsion system of a REMUS-100 AUV deployed near a fixed array near Honolulu Harbor, Hawaii, by fusing measured acoustic data with multi-sensor navigational records recorded on th...