Characterization of the Innomar Deep 36 Sub-Bottom Profiler in the Gulf of Mexico

A sound source characterization (SSC) of the Innomar Deep-36 sub-bottom profiler was conducted in waters <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 10\mathbf{m}$</tex> deep in the north western corner of the Gulf of Mexico. Pre-survey modeling assessed the safe distance for very-high frequency mammals exposed to the SBP to be 1100 m. The SSC directly measured the safe distance for marine mammals exposed to the SBP to be 160 m. The SSC assessed several parameters of the Deep-36 and found them to be substantially different than were assumed during pre-survey modeling. The most notable difference was that the beampattern of the Deep-36 is not circular, rather, it is much wider across-track than along track, with broadside sidelobes <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\sim 26\mathbf{dB}$</tex> higher than those at endfire.