Marine and Environmental Sciences Centre and Institute of Marine Research, University of the Azores, Horta, Portugal, Department of Oceanography and Fisheries, University of the Azores, Horta, Portugal, Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, Suffolk, UK, Hawaii Institute of Marine Biology, University of Hawaii, Kaneohe, HI, USA, Oceanwide Science Institute, Honolu...

Direction-of-arrival (DOA) estimation in a spatially isotropic white noise background has been widely researched for decades. However, practice, such as underwater acoustic ambient shallow water, the can be colored, which may severely degrade performance of DOA estimation. To solve this problem, paper proposes method based on sparse Bayesian learning with modified model using vector hydrophone ...

xi Acknowledgements xii Chapter

Knowledge of the noise probability density function (PDF) is central in signal detection problems, not only for optimum receiver structures but also for processing procedures such as power normalization. Unfortunately, the statistical knowledge must be acquired since the classical assumption of a Gaussian noise PDF is often not valid in underwater acoustics. In this report, we study statistical...

Autonomous underwater vehicles (AUVs) are typically used to “actively” probe the ocean, using sensors that are mounted on a vehicle that moves through the water column. A more challenging task is to use an AUV to position a bottom-mounted stationary platform, such as a passive sonar that requires a large aperture. This paper describes the development of a passive sonar, which was mounted as a p...

In order to explore marine natural resources using remote robotic sensor or to enable rapid information exchange between ROV (remotely operated vehicles), AUV (autonomous underwater vehicle), divers, and ships, ultrasonic underwater communication systems are used. However, if the communication system is applied to rich living creature marine environment such as shallow sea, it suffers from gene...

This paper investigates the acoustic behavior of underwater air-filled resonators that could potentially be used in an underwater noise abatement system. The resonators are similar to Helmholtz resonators without a neck, consisting of underwater inverted air-filled cavities with combinations of rigid and elastic wall members, and they are intended to be fastened to a framework forming a station...

In recent years the volume and spatial extent of anthropological noise pollution of the oceans has become clearer as underwater acoustic research has matured in the open literature following the run-down of the cold war. In parallel, the range, depth and dependence of marine mammals on sound for communication and environmental sensing has been brought sharply into focus by an increased attentio...