In this paper we discuss challenging issues related to positioning in underwater acoustic networks focussing in the major goal of establishing a common coordinate system which should allow applications to perform collaborative sensing tasks such as identification, detection, and/or tracking of sea targets. A general description of the most important positioning methods and algorithms which have...

A major high-frequency sediment acoustics experiment was conducted in shallow waters of the northeastern Gulf of Mexico. The experiment addressed high-frequency acoustic backscattering from the seafloor, acoustic penetration into the seafloor, and acoustic propagation within the seafloor. Extensive in situ measurements were made of the sediment geophysical properties and of the biological and h...

Ocean gliders are quiet, buoyancy-driven, long-endurance, profiling autonomous platforms. Gliders therefore possess unique advantages as platforms for Passive Acoustic Monitoring (PAM) of the marine environment. In this paper, we review available glider and passive acoustic monitoring systems, explore current potential uses monitoring-equipped study physical oceanography, biology, ecology regul...

acoustic neuromas (an) are schwann cell-derived tumors that commonly arise from the vestibular portion of the eighth cranial nerve also known as vestibular schwannoma(vs) causes unilateral hearing loss, tinnitus, vertigo and unsteadiness. in many cases, the tumor size may remain unchanged for many years following diagnosis, which is typically made by mri. in the majority of cases the tumor is s...

The prediction of the acoustic field evolution on a day to week frame, in a given oceanic area, is an important issue in sonar performance modeling. It relies primarily on acoustic propagation models, which convert water column and geometric/geoacoustic parameters to ‘instantaneous’ acoustic field estimates. In practice, to model the acoustic field, even the most accurate acoustic models have t...

diesel exhaust particles are a complex mixture of thousands of gases and fine substances that contain more than 40 different environmental contaminants. being exposed to these exhaust particles (called soot) can cause lung damage and respiratory problems. diesel particulate filters are used in many countries for mobile sources as a legal obligation to decrease harmful effect of these fine parti...

Variability in the ocean environment can greatly impact acoustic propagation. Sonar systems often show large performance differences depending on location and oceanographic conditions. The long term goals of this research is to better understand the fundamental environmental quantities that impact shallow water acoustic propagation and to develop techniques for both characterizing the environme...