Bottom characterization in the northern Gulf of Mexico using chirp sonar and ship noise data

Abstract

As a part of Prof. George Ioup’s multi-institutional research initiative, chirp sonar bottom surveys were conducted near the Mississippi Canyon in the northern Gulf of Mexico during the Littoral Acoustic Demonstration Center (LADC) 2001 experiment. Bottom geoacoustic properties were estimated using a shallow-towed 2–12 kHz chirp sonar that provided sub-meter resolution and 60 m penetration. The inversion results showed that the experimental site is mainly covered with clayey sediment. In 2010, a second bottom characterization experiment was conducted at ∼25 miles NE of the LADC 2001 experiment site using a deep-towed chirp sonar. Deep-towed chirp sonar provided geoacoustic property estimations as well as low-grazing-angle bottom-loss measurements. As a source of opportunity, own-ship noise data were also used for geoacoustic parameter estimation and bottom-loss measurements. Geoacoustic parameter estimations and bottom loss measurements from the chirp-sonar and ship-noise data provided similar results that were also in agreement with those from the LADC 2001 experiment. [Work supported by ONR.]