Featured Research

from universities, journals, and other organizations

Breakthrough Mine-detection Turns Ocean Floor 'Transparent'

Date:
March 1, 2004
Source:
North Carolina State University
Summary:
Navies worldwide employ a host of mine-detection technologies and techniques, most of them complicated, expensive, and far from perfect. So a simpler, more effective method for detecting these mines, developed by a physicist at North Carolina State University, could make big waves in naval headquarters around the globe.

Since 1776, when naval mines were invented, navies have rightfully feared the stealthy and relatively simple weapons, which can disable or destroy warships and paralyze vital shipping. Navies worldwide employ a host of mine-detection technologies and techniques, most of them complicated, expensive, and far from perfect. So a simpler, more effective method for detecting these mines, developed by a physicist at North Carolina State University, could make big waves in naval headquarters around the globe.

Unlike current mine-detection techniques, the patented methodology finds objects buried in the ocean floor without the use of complex, unreliable modeling and without the usual arrays of sonar transmitters and receivers. Instead, the method records the return echo of a sonar transceiver's "ping," then time-reverses and transmits that signal. The following echo clearly shows buried objects, and suppresses the response from the seafloor itself, making the underwater terrain "transparent."

Dr. David M. Pierson, then a doctoral student in physics at NC State, demonstrated the new approach in research he conducted with Dr. David E. Aspnes, Distinguished University Professor of Physics, in late 2003. The project was supported by a grant from the Office of Naval Research. Pierson has since joined the Applied Physics Laboratory of Johns Hopkins University in Baltimore, where his work is supported in part by the U.S. Navy.

"The method has not been explored as a solution to this problem until now," said Pierson. "Using time reversal on the return echoes back scattered by buried mines gave us results we considered amazing."

According to Aspnes, the young physicist's research is a breakthrough. "Time reversal is a technique that has been used before in various contexts, including optics and acoustics, but before Pierson's work the advantages of time reversal for isolating targets in backscattered signals was never before recognized."

Using time reversal to find buried mines requires only one transceiver, said Pierson, although more can be used, and the method isn't limited by the composition of the ocean floor. "Previous methods had to incorporate a lot of complex modeling of the seafloor and the ocean environment," Pierson said, "and required sophisticated software and hardware systems. My time-reversal technique not only simplifies the needed equipment, but also can be implemented using existing sonar equipment, with minor software changes. More elaborate analyses of echoes are also made possible."

What Pierson has done, said Aspnes, is to demonstrate a new approach that uses sonar but is simpler and works better than any previous method. "In Pierson's approach," he said, "a 'ping' is first transmitted from a sonar transceiver. The return echo is then recorded, time-reversed, and transmitted. He discovered that in the next echo the response from the seafloor was suppressed, but the echo from buried objects was enhanced. This enhancement is seen even if the signal from the buried object is too small to be detected in the first return."

The NC State discovery should please naval mine-detection experts, who now use everything from dolphins to divers to sophisticated software modeling and elaborate sonar arrays in their grim work. And it should send those who design such mines back to their equally grim drawing boards.


Story Source:

The above story is based on materials provided by North Carolina State University. Note: Materials may be edited for content and length.


Cite This Page:

North Carolina State University. "Breakthrough Mine-detection Turns Ocean Floor 'Transparent'." ScienceDaily. ScienceDaily, 1 March 2004. <www.sciencedaily.com/releases/2004/02/040229231811.htm>.
North Carolina State University. (2004, March 1). Breakthrough Mine-detection Turns Ocean Floor 'Transparent'. ScienceDaily. Retrieved October 21, 2014 from www.sciencedaily.com/releases/2004/02/040229231811.htm
North Carolina State University. "Breakthrough Mine-detection Turns Ocean Floor 'Transparent'." ScienceDaily. www.sciencedaily.com/releases/2004/02/040229231811.htm (accessed October 21, 2014).

Share This



More Earth & Climate News

Tuesday, October 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Traditional Farming Methods Gaining Ground in Mali

Traditional Farming Methods Gaining Ground in Mali

AFP (Oct. 20, 2014) He is leading a one man agricultural revolution in Mali - Oumar Diatabe uses traditional farming methods to get the most out of his land and is teaching others across the country how to do the same. Duration: 01:44 Video provided by AFP
Powered by NewsLook.com
Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-Fuel Impala

3BL Media (Oct. 20, 2014) Hey, Doc! Sewage, Beer and Food Scraps Can Power Chevrolet’s Bi-fuel Impala Video provided by 3BL
Powered by NewsLook.com
White Rhino's Death In Kenya Means Just 6 Are Left

White Rhino's Death In Kenya Means Just 6 Are Left

Newsy (Oct. 20, 2014) Suni, a rare northern white rhino at Ol Pejeta Conservancy, died Friday. This, as many media have pointed out, leaves people fearing extinction. Video provided by Newsy
Powered by NewsLook.com
New Organic Fertilizer Helps Reforestation of Monarch Butterflies’ Winter Retreat

New Organic Fertilizer Helps Reforestation of Monarch Butterflies’ Winter Retreat

Reuters - Innovations Video Online (Oct. 20, 2014) Using an organic fertiliser, a conservationist from the National Autonomous University of Mexico (UNAM), leads an award-winning project to reforest the sanctuary of monarch butterflies. Sharon Reich reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins