Model-informed acoustic source localization by an underwater glider in a bathymetrically complex seamount region with Gulf Stream influence

Underwater gliders provide a quiet and efficient platform for ocean acoustic research given their near silent operation and collocated sound-speed measurements. During the New England Seamount Acoustics Experiment (NESMA), we deployed an underwater glider equipped with a multi-channel passive acoustic hydrophone system. We utilized this platform to study multi-path propagation and source/receiver localization in a bathymetrically complex seamount environment with Gulf Stream influence. A set of propagation experiments were conducted between an acoustic source moored to the top of the Atlantis II seamount and the mobile glider receiver. The acoustic source emitted mid-frequency linear frequency modulated (LFM) pulses for 5 min every hour from a nominal depth of 900 m. The glider carried the tetrahedral hydrophone system along a transect that crossed over the top of the seamount, yielding a dataset indicating range-dependency in the measured sound-speed profiles. LFM pulse receptions on the glider receiver from the surface to 1000 m in depth and 3.5 km to over 50 km in range have been identified. These observed multi-path arrival structures are utilized, alongside an acoustic propagation model, to study glider-based localization of mid-frequency sources. This work illustrates the potential for a glider-based acoustic monitoring network capable of varied source localization.