Geacoustic inversion using autonomous underwater vehicles

Autonomous underwater vehicles (AUV's) are valuable for bottom geoacoustic studies because they can remain in close proximity to the seafloor, maneuver accurately along underwater tracks, and perform multi-platform operations. A REMUS 100 AUV was deployed in the recent Seabed Characterization Experiment, sponsored by the Office of Naval Research (ONR) and conducted in the New England Mud Patch Area from March to April 2017. This AUV was equipped with a sound source transmitting acoustic chirp signals from 800 to 1300 Hz and a 20 m-long digital thin line towed array (DTLA) receiving both the AUV source signals and acoustic signals transmitted from different sources. The AUV track was along a path between a moored source and a fixed receiver sled. With this experimental configuration, three different geoacoustic approaches were investigated: (1) bottom reflection inversion using the AUV source and the towed DTLA, (2) range dependent broadband acoustic inversion using the moving AUV source and the fixed rece...