Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Engineers develop low-cost, highly sensitive underwater listening device

23.05.2005


Ocean-going acoustic sensor array to aid in national security, ocean research efforts



Jason Holmes, a mechanical engineering graduate student at Boston University and guest researcher at Woods Hole Oceanographic Institute, has devised a low-cost, highly sensitive array of underwater ears that is perking up interest in both homeland security and ocean research circles. Holmes’ device -- an underwater hydrophone array designed to be towed by a small, autonomous submarine -- can monitor for ocean-going threats to America’s waterways or for sound for ocean acoustics studies.

Holmes will present research on his underwater listening device in Vancouver on May 20 at the semi-annual meeting of the Acoustical Society of America.


The array combines sophisticated engineering with off-the-shelf hardware to create a relatively inexpensive but highly sensitive underwater listening device. The prototype comprises six underwater microphones, or hydrophones, spaced inside a 30-foot plastic tube filled with mineral oil. The array tube is filled with mineral oil to create neutral buoyancy, allowing the array to float behind the underwater towing vehicle.

Signals from the hydrophones are captured and stored on mini-disc recorders aboard the unpiloted submarine, which is called Remus. Designed by Woods Hole Oceanographic Institution, Remus looks like a small torpedo and can navigate autonomously underwater around obstacles and through harbors using GPS sensors, sonar, and electronic maps.

Listening arrays typically used by the military and ocean scientists are towed behind ships and are very long, the shortest being around 1,500 feet long, and are several inches in diameter. At 30 feet in length and 1.1 inches in diameter, the extremely compact prototype can easily be towed through the water by a small, quiet, battery-powered craft. The compact size of the towing sub and array make it easy for one or two people to launch the system, compared to the fully crewed ships required for conventional hydrophone systems.

Holmes originally developed the array to help him study how sound waves travel through shallow water, where sound is refracted by the bottom. Until recently, most acoustic ocean studies have been conducted in deep water, where the bottom has little effect on sound. Holmes constructed the hydrophone system to tackle the problem of how sound waves behave in shallow water, but the U.S. Navy saw the device as a potential security tool, one that is vastly less expensive than the multi-million dollar listening arrays currently in use. Parts for Holmes’ array cost a mere $4,000 and are available as off-the-shelf technology.

Holmes is now working with the military to further develop the array for underwater intelligence gathering. Holmes says his next project will comprise four underwater hydrophone arrays towed by a fleet of unpiloted subs that could travel up to 4 kilometers per trip. Holmes and his faculty advisor William Carey, a professor of aerospace and mechanical engineering in BU’s College of Engineering, say they envision a fleet of entirely autonomous listening subs will prowl the seas, returning to underwater recharging stations to upload their data and refresh their batteries.

"A lot of people were skeptical this would even work," Carey says. "But the way Jason has designed this array, this will change the way ocean measurements are made."

Ann Marie Menting | EurekAlert!
Further information:
http://www.bu.edu

More articles from Power and Electrical Engineering:

nachricht A big nano boost for solar cells
18.01.2017 | Kyoto University and Osaka Gas effort doubles current efficiencies

nachricht Multiregional brain on a chip
16.01.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

All articles from Power and Electrical Engineering >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>