Ocean tomography with acoustic daylight

Acoustic Daylight Imaging: Vision in the Ocean

Sound provides a natural means for exploring the ocean but current sonar systems, as used for example in swath-mapping applications, do not provide directly pictorial images of the ocean depths. Such systems are more akin to radar, which relies on travel-time information to map the environment. A new acoustic technique for providing real-time visual images of the interior of the ocean is curren...

Ocean Acoustic Tomography

The idea of using the sound to monitor the changes in the marine environment motivated the oceanographers to develop the concept of ocean acoustic tomography. Starting from the early 80’s when the pioneers started to pave the way leading to the acoustical monitoring of the ocean change and coming to the beginning of the new millennium, several achievements in the field can be reported vindicati...

Ocean acoustic tomography structured covariance estimation

Classic Ocean Acoustic Tomography by Wiener inversion needs good estimates of the noises power affecting the errors between the in situ measurements of the travel times and their estimates obtained by reliable simulations. We investigate the maximum likelihood estimation of a structured covariance matrix, whose subspaces of interest are known, but whose associated powers are unknown. Using the ...

An autonomous system for ocean acoustic tomography

Ray Tracing for Ocean Acoustic Tomography

This report describes a new, flexible computer code in the FORTRAN computer language to make ray calculations for ocean acoustic tomography. The Numerical Recipes software package provided the basis for much of this computer code. The ray equations are reviewed, and ray equations that include the effects of ocean current are derived. Methods are derived for rapidly integrating those equations t...