PRESS-NEWS.org - Press Release Distribution
PRESS RELEASES DISTRIBUTION

MIT's Lincoln Lab: Seeing through walls

Researchers at MIT's Lincoln Lab have developed new radar technology that provides real-time video of what's going on behind solid walls

2011-10-19
(Press-News.org) CAMBRIDGE, Mass. -- The ability to see through walls is no longer the stuff of science fiction, thanks to new radar technology developed at MIT's Lincoln Laboratory.

Much as humans and other animals see via waves of visible light that bounce off objects and then strike our eyes' retinas, radar "sees" by sending out radio waves that bounce off targets and return to the radar's receivers. But just as light can't pass through solid objects in quantities large enough for the eye to detect, it's hard to build radar that can penetrate walls well enough to show what's happening behind. Now, Lincoln Lab researchers have built a system that can see through walls from some distance away, giving an instantaneous picture of the activity on the other side.

The researchers' device is an unassuming array of antenna arranged into two rows — eight receiving elements on top, 13 transmitting ones below — and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially "urban combat situations," says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project.

Waves through walls

Walls, by definition, are solid, and that's certainly true of the four- and eight-inch-thick concrete walls on which the researchers tested their system.

At first, their radar functions as any other: Transmitters emit waves of a certain frequency in the direction of the target. But in this case, each time the waves hit the wall, the concrete blocks more than 99 percent of them from passing through. And that's only half the battle: Once the waves bounce off any targets, they must pass back through the wall to reach the radar's receivers — and again, 99 percent don't make it. By the time it hits the receivers, the signal is reduced to about 0.0025 percent of its original strength.

But according to Charvat, signal loss from the wall is not even the main challenge. "[Signal] amplifiers are cheap," he says. What has been difficult for through-wall radar systems is achieving the speed, resolution and range necessary to be useful in real time. "If you're in a high-risk combat situation, you don't want one image every 20 minutes, and you don't want to have to stand right next to a potentially dangerous building," Charvat says.

The Lincoln Lab team's system may be used at a range of up to 60 feet away from the wall. (Demos were done at 20 feet, which Charvat says is realistic for an urban combat situation.) And, it gives a real-time picture of movement behind the wall in the form of a video at the rate of 10.8 frames per second.

Filtering for frequencies

One consideration for through-wall radar, Charvat says, is what radio wavelength to use. Longer wavelengths are better able to pass through the wall and back, which makes for a stronger signal; however, they also require a correspondingly larger radar apparatus to resolve individual human targets. The researchers settled on S-band waves, which have about the same wavelength as wireless Internet — that is, fairly short. That means more signal loss — hence the need for amplifiers — but the actual radar device can be kept to about eight and a half feet long. "This, we believe, was a sweet spot because we think it would be mounted on a vehicle of some kind," Charvat says.

Even when the signal-strength problem is addressed with amplifiers, the wall — whether it's concrete, adobe or any other solid substance — will always show up as the brightest spot by far. To get around this problem, the researchers use an analog crystal filter, which exploits frequency differences between the modulated waves bouncing off the wall and those coming from the target. "So if the wall is 20 feet away, let's say, it shows up as a 20-kilohertz sine wave. If you, behind the wall, are 30 feet away, maybe you'll show up as a 30-kilohertz sine wave," Charvat says. The filter can be set to allow only waves in the range of 30 kilohertz to pass through to the receivers, effectively deleting the wall from the image so that it doesn't overpower the receiver.

Monitoring movement

In a recent demonstration, Charvat and his colleagues, Lincoln Lab assistant staff John Peabody and former Lincoln Lab technical staff Tyler Ralston, showed how the radar was able to image two humans moving behind solid concrete and cinder-block walls, as well as a human swinging a metal pole in free space. The project won best paper at a recent conference, the 2010 Tri-Services Radar Symposium.

Because the processor uses a subtraction method — comparing each new picture to the last, and seeing what's changed — the radar can only detect moving targets, not inanimate objects such as furniture. Still, even a human trying to stand still moves slightly, and the system can detect these small movements to display that human's location.

The system digitizes the signals it receives into video. Currently, humans show up as "blobs" that move about the screen in a bird's-eye-view perspective, as if the viewer were standing on the wall and looking down at the scene behind. The researchers are currently working on algorithms that will automatically convert a blob into a clean symbol to make the system more end-user friendly. "To understand the blobs requires a lot of extra training," Charvat says.

With further refinement, the radar could be used domestically by emergency-response teams and others, but the researchers say they developed the technology primarily with military applications in mind. Charvat says, "This is meant for the urban war fighter … those situations where it's very stressful and it'd be great to know what's behind that wall."

###

END



ELSE PRESS RELEASES FROM THIS DATE:

Recent Court Ruling Will Reduce Amount of Money Awarded to Plaintiffs

2011-10-19
The Supreme Court of California recently denied plaintiff Rebecca Howell full compensation for her medical expenses from Hamilton Meats & Provisions, the company whose truck struck Hamilton's vehicle while making an illegal u-turn. As a result of the accident, Howell suffered through two spinal surgeries, among other medical treatments. The initial bill for her medical expenses came to almost $190,000. Fortunately, Howell had the foresight to purchase health insurance to cover unforeseen medical costs like these, but doing so denied her almost $130,000. It turned ...

Cyber war might never happen

2011-10-19
Cyber war, long considered by many experts within the defence establishment to be a significant threat, if not an ongoing one, may never take place according to Dr Thomas Rid of King's College London. In a paper published in The Journal of Strategic Studies, Dr Thomas Rid, from the Department of War Studies, argues that cyber warfare has never taken place, nor is it currently doing so and it is unlikely to take place in the future. Dr Rid said: 'The threat intuitively makes sense: almost everybody has an iPhone, an email address and a Facebook account. We feel vulnerable ...

Technology targets genetic disorders linked to X chromosome

2011-10-19
Geneticists at Emory University School of Medicine have demonstrated a method that enables the routine amplification of all the genes on the X chromosome. The technology allows the rapid and highly accurate sequencing and identification of novel genetic variants affecting X chromosome genes. The method, developed in cooperation with RainDance Technologies (www.RainDanceTech.com), is described in the Oct. 2011 issue of Genomics. Senior author Michael Zwick, PhD, assistant professor of human genetics at Emory University School of Medicine, is using the method to identify ...

Piecing together the priceless 'Cairo Genizah'

Piecing together the priceless Cairo Genizah
2011-10-19
A well-known collection of historical texts, the Cairo Genizah is one of the most valuable sources of primary documents for medieval historians and religious scholars. The 350,000 fragments found in the Genizah include not only religious texts, but also social and commercial documents, dating from the 9th to 19th century. But the collection is scattered among 70 institutions worldwide, including libraries in Cambridge, Jerusalem, and New York City, and scholars are hampered by both the wide dispersal of the collection as well as their fragmentary condition. Now researchers ...

HOA Fees Can Still Be Assessed After Foreclosure and Even After Bankruptcy

2011-10-19
Homeowners continue to feel the effects of the recession as banks drag their feet to foreclose on properties that have long been abandoned. While this does not normally cause an additional financial impact to homeowners -- especially those who have already filed bankruptcy -- some borrowers who previously paid homeowners association (HOA) fees will still be liable for these charges until the foreclosure is complete and the bank takes ownership of a property. Homeowners who experience this should consult a foreclosure and bankruptcy attorney. Why Are Homeowners Liable ...

Researchers discover why steroid treatment for COPD is ineffective

2011-10-19
Chronic obstructive pulmonary disease (COPD) leads to persistent inflammation of the airways and is typically managed with corticosteroids, a class of anti-inflammatory medication. However, corticosteroids do not improve survival nor alter the progression of COPD and may reduce lung symptoms as little as 20 percent. A new study led by researchers at the Johns Hopkins Bloomberg School of Public Health, found why corticosteroids do not work well for COPD patients and how additional treatment with sulforaphane—an ingredient of broccoli and other vegetables—can improve the ...

NJ Status of Same-Sex Marriages, Domestic Partnerships and Civil Unions

2011-10-19
The law regarding same-sex couples and marital status is beginning to change rapidly in many parts of the country. New Jersey has been no exception. In 2004, the New Jersey Legislature passed a domestic partnership law. In 2007, it enacted a law allowing civil unions. New Jersey also recognizes same-sex marriages performed out-of-state. Gay and lesbian couples in New Jersey today can choose whether to register their domestic partnership to receive some of the rights and obligations of marriage or apply for a civil union license to receive substantially all the rights ...

From tropics to poles: Study reveals diversity of life in soils

From tropics to poles: Study reveals diversity of life in soils
2011-10-19
Microscopic animals that live in soils are as diverse in the tropical forests of Costa Rica as they are in the arid grasslands of Kenya, or the tundra and boreal forests of Alaska and Sweden. That conclusion is found in research results published today in the journal Proceedings of the National Academy of Sciences. Scientists have generally accepted that a wider range of species can be found above ground at the equator than at the Earth's poles. But this study proves for the first time that the same rules don't apply to the nematodes, mites and springtails living ...

Columbia SC Hotel Provides Nearby Lodging to The American Institute of Architects South Carolina Chapter 2011 Conference

2011-10-19
The Hilton Garden Inn Hotel in Columbia SC (Northeast) offers convenient lodging to architects attending the AIASC 2011 Fall Conference. The event will take place October 20-22 at the Columbia Metropolitan Convention Center. The conference is open to members of the American Institute of Architects - South Carolina Chapter. The group is comprised of over 900 people including licensed architects, emerging professionals and allied partners who are committed to excellence in design and livability for South Carolina's buildings and communities. The AIASC Conference workshop ...

Fatal crashes in the US: Fewer Canadian drivers under the influence

2011-10-19
A new study by researchers at the Johns Hopkins Center for Injury Research and Policy and Columbia University finds alcohol-related fatal motor vehicle crashes in the U.S. are much lower among drivers with Canadian licenses than drivers with U.S. or Mexican licenses. The prevalence of alcohol involvement in fatal crashes was 27 percent for both U.S. and Mexican drivers, and 11 percent for Canadian drivers. Similarly, alcohol impairment was found in 23 percent of U.S. and Mexican drivers and 8 percent of Canadian drivers involved in a fatal crash. Research from other countries ...

LAST 30 PRESS RELEASES:

Music-based therapy may improve depressive symptoms in people with dementia

No evidence that substituting NHS doctors with physician associates is necessarily safe

At-home brain speed tests bridge cognitive data gaps

CRF appoints Josep Rodés-Cabau, M.D., Ph.D., as editor-in-chief of structural heart: the journal of the heart team

Violent crime is indeed a root cause of migration, according to new study

Customized smartphone app shows promise in preventing further cognitive decline among older adults diagnosed with mild impairment

Impact of COVID-19 on education not going away, UM study finds

School of Public Health researchers receive National Academies grant to assess environmental conditions in two Houston neighborhoods

Three Speculum articles recognized with prizes

ACM A.M. Turing Award honors two researchers who led the development of cornerstone AI technology

Incarcerated people are disproportionately impacted by climate change, CU doctors say

ESA 2025 Graduate Student Policy Award Cohort Named

Insomnia, lack of sleep linked to high blood pressure in teens

Heart & stroke risks vary among Asian American, Native Hawaiian & Pacific Islander adults

Levels of select vitamins & minerals in pregnancy may be linked to lower midlife BP risk

Large study of dietary habits suggests more plant oils, less butter could lead to better health

Butter and plant-based oils intake and mortality

20% of butterflies in the U.S. have disappeared since 2000

Bacterial ‘jumping genes’ can target and control chromosome ends

Scientists identify genes that make humans and Labradors more likely to become obese

Early-life gut microbes may protect against diabetes, research in mice suggests

Study raises the possibility of a country without butterflies

Study reveals obesity gene in dogs that is relevant to human obesity studies

A rapid decline in US butterfly populations

Indigenous farming practices have shaped manioc’s genetic diversity for millennia

Controlling electrons in molecules at ultrafast timescales

Tropical forests in the Americas are struggling to keep pace with climate change

Brain mapping unlocks key Alzheimer’s insights

Clinical trial tests novel stem-cell treatment for Parkinson’s disease

Awareness of rocky mountain spotted fever saves lives

[Press-News.org] MIT's Lincoln Lab: Seeing through walls
Researchers at MIT's Lincoln Lab have developed new radar technology that provides real-time video of what's going on behind solid walls