KATSINA, Nigeria - A Nigerian state governor survived a car crash that left four dead as he traveled to meet the president in the oil-rich country's north. Lincoln Laboratory
researchers John Peabody and Gregory Charvat explains how their team’s system can see through walls. Video: Melanie Gonick 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 wallsWalls, 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 frequenciesOne 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 trade miner review 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.“It’s a very capable system mainly because of its real-time imaging capability,†says Robert Burkholder, a research professor in Ohio State University’s Department of Electrical and Computer Engineering who was not involved with this work.
“It also gives very good resolution, due to digital processing and advanced algorithms for image processing.
It’s a little bit large and bulky for someone to take out in the field,†he says, but agrees that mounting it on a truck would be appropriate and useful.Monitoring
movementIn 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.â€We asked you to send us photos of your favorite walks in Europe. Here are some
highlights. More than 20 galleries have set up in Al Quoz in the past couple of years, attracted by the large spaces available and the neighborhood’s gritty, urban feel. A brand new factory in Bangalore is expected to assemble 30,000 units of Mahindra Reva’s E2O annually.
Thanks for being such a loyal audience. Bye-bye, so long, and farewell.
The
author of this week’s cover article answers questions about the power struggle at NBC’s morning show — and why it matters.
Haitian President René Préval pleaded Wednesday for U.S.
help plugging a multimillion-dollar budget gap caused by the Jan. 12 earthquake but said he got a cool reception from congressional leaders wary of handing over cash. National Geographic belongs to a rare breed of magazine — the sort with a shelf life as long as a book’s. When back issues of other periodicals are tossed to the garbage, yellow-bordered, photo-filled volumes end up on living room shelves and in attic boxes, maybe gathering dust but still too precious for their owner to part with. Read full article >> US Airways lost its aggressive takeover bid for Delta Air Lines yesterday when Delta's creditors rejected the $10 billion offer that would have created the nation's largest carrier.
Tensions are high in Venezuela as opposition leader Henrique Capriles pressures the National Electoral Council to permit a complete audit of the April 14 presidential election. Well-heeled consumers will never find it hard to splash out on sustainable mod-cons, but is concept truly clickbank pirate download home that Max O'Flaherty designed – which won his firm a coveted EU award at the Royal Institute of British Architects annual awards last month –
nearly didn't get built at all.The
House on Mount Anville, which put his practice, Aughey O'Flaherty, in the same bracket as star architects such as Zaha Hadid, was almost denied planning permission on the grounds that it would not have been sustainable to knock down its precursor: a 1970s bungalow."It was
a leaky, drafty, poorly insulated house and there wasn't much architectural merit," says O'Flaherty. Thankfully, he and his team were able to demonstrate to the council that replacing it with a new glass, brick and timber structure which would be far more energy efficient.In
his design, super insulation, an airtight frame and triple-glazed windows are employed to maximise solar gain and reduce CO2 emissions.
"We could show that, very quickly – after year four or five – that there would be a net gain; that it would be more sustainable compared to the old house, and even a refurbished house."Slow progressFor O'Flaherty, it is "infuriating" that more houses are not built to greener standards.
Homes can be fitted with photovoltaic
panels, geothermal collectors and other hyper-efficient systems and sensors
that adjust to minute changes in humidity or temperature, but sometimes "first principles", such as using simple materials and positioning a building so that rooms follow the path of the sun, are all you need, he says.O'Flaherty added: "The construction industry is a very slow industry to change. If you are a house builder you want the lowest common denominator.
You want the cheapest way from A to Z and you go with the
norm."If you've got 100 houses and 95% are built in the traditional way and 5% in a more proactive way, it needs to be a particular consumer to go for the 5% – early adopters, forward-thinking people."Non-conventional
solutionsO'Flaherty's response has been, rather cannily, to begin offering buyers an off-the-shelf eco home for a couple of hundred thousand euros. It involves modular timber frame with thick thermal insulation, giving
it an impressive BER A1 rating.
It's early days, but it's a concept which has been successfully scaled up in some parts of Europe, and which he thinks could
attract environmentally conscious consumers closer to home.Germany is one country where this kit eco house concept has blossomed, growing from a cottage industry into a major sector. WeberHaus, for instance, has built around 20,000 energy efficient "preconfigurated" houses across Europe since 1990, such as Passive Houses, a type of ultra-low energy home.A
WeberHaus home can be built for about €200,000, says Holger Heid, the company's product manager.
"If you compare the fuel, gas, electricity and other energy bills of a WeberHaus with a city flat, you can with our house easily [save] a quarter or fifth."The market in Germany is however buoyed by a regulatory environment, which heightens the attractiveness of eco homes. "It depends a lot on the national building regulation," says Heid. "The more stringent the regulation is, the more eco homes become a mass product and thus a mass market."Elsewhere in the world, price is
often a major obstacle. For many, living in eco home will seem about as obtainable as living in a Palladian villa overlooking Lake Como. "For the moment we can talk about the eco house concept like a niche market," says Ruxandra Stefanescu, of Romanian architectural practice Soleta.However,
she says that a number of drivers are boosting their allure. "Rising energy prices, the availability of a greater number of technologies and materials … and the mandatory assessment of buildings in terms of energy efficiency represent a favourable context.""When
you are depending on the public electricity network and when you can't control the price, then you start looking for non-conventional solutions."Bringing sustainable homes in to the mainstreamOne NGO pushing the case for a scaling up of eco housing on an international scale is the World Green Building Council.
aquaponics 4 you recently released a report, The Business Case for Green Building, which showed a serious mismatch between the actual costs of green buildings and developers' expectations. While the typical cost compared to conventional buildings ranged from minus 0.4%
to a high of 12.5%, the report showed developers would often estimate the cost at up to 29% more.James Drinkwater, senior policy advisor to the WGBC's Europe regional network, suggests that by continuing to collaborate on sustainable building design, the industry will not only get a better steer on costs, but in turn prices will be driven down."Breaking down the silos and creating collaboration in the supply chain is key to scaling
up the production of sustainable homes," he says, hinting that momentum is moving in the right direction."There has been an overall trend towards the reduction in design and construction costs associated with green building as building codes around the world become stricter, supply chains for green materials and technologies mature
and the industry becomes more skilled at delivering green buildings," he says.The backing of large developers is, of course, essential for improving the share of sustainable homes. "There are developers who are passionate advocates of green building, and there are developers who are sustainability laggards," says Drinkwater."Unfortunately in some countries the latter group are shouting the loudest and so policymakers are less inclined to transition towards higher standards for fear it will slow down the provision of housing."For
O'Flaherty, if eco housing is ever to become truly mass scale, better advocacy and communication by business is fundamental. In this way, it's more than just a case of changing policy, it's about a wholesale change of direction."You just have to keep banging the drum that there's a smarter way to build," he says.This content is brought to you
by Guardian Professional.
Become GSB member to get more stories like this direct to your inboxScaling upSustainabilityWill Henleyguardian.co.uk
© 2013 Guardian News and Media Limited or its affiliated companies. All rights reserved. | Use of this content is subject to our Terms & Conditions | More Feeds To understand why drug resistance often causes targeted cancer therapies to fail, geneticists have teamed up with mathematicians to
create detailed models of cancer.
The "tea party" movement is not racist, Vice President Biden said, though he believes that some of those involved in the movement have expressed racist views. Lawmakers embarked Tuesday on an uphill battle to delay a controversial law that would reduce the fees banks receive from merchants each time a debit card is swiped.
Mayor Adrian M. Fenty's nominee to lead the city's Homeland Security and Emergency Management Agency was unanimously approved Tuesday by a D.C. Council committee, despite her lack of experience in the field. The nomination still has to be approved by the full council. No injuries have been reported.
Johnny O’Callaghan wrote a play, opening next week, about the resistance he met when trying to adopt a 3-year-old. Frank Stranahan, the premier amateur of his era who contended for majors and was the first notable
player to make fitness a regimen in golf, has died.
He was 90. Barack Obama praises former secretary of homeland security, saying Americans are 'safer and more secure' thanks to herBarack Obama's secretary for homeland security, Janet Napolitano, resigned on Friday to take a senior post running the University of California.Napolitano,
the first woman to hold the post, has been a close confidante to the president, leading the administration's response to natural disasters and terrorist threats. She has also been a strong supporter of the comprehensive immigration reform proposed in a Senate bill, which would provide a landmark route to citizenship for millions of workers in the country illegally.The timing of her departure could unnerve the White House, which is grappling with how to overcome opposition to wholescale immigration among House Republicans. Obama said in a statement that Napolitano had dealt with "some of
[the] toughest challenges" facing the US."Since day one, Janet has led my fat loss factor to secure our borders, deploying a historic number of resources, while also taking steps to make our immigration system fairer and more consistent with our values," Obama said. "And the American people are safer and more secure thanks to Janet's leadership
in protecting our homeland against terrorist attacks."The
LA Times, which broke news of her resignation, said Napolitano had been head-hunted for president for the University of California, an unusual move given such posts are normally granted to senior academics. "While some may consider her to be an unconventional choice, secretary Napolitano is without a doubt
the right person at the right time to lead this incredible university," Sherry Lansing, the regent and former film industry executive who headed the search committee, said in a statement to the newspaper.
"She will bring fresh eyes and a new sensibility – not only to UC, but to all of California.
She will stand as a vigorous advocate for faculty, students and staff at a time when great changes in our
state, and across the globe, are presenting as many opportunities as challenges."Napolitano, 55, a former governer of Arizona, has led the department for homeland security, which has an annual $60bn budget and 240,000 employees, since 2009.She
has had an often fractious relationship with Republicans on Capitol Hill, not least over her stance on immigration reform, which looks likely to become an issue of ongoing and protracted debate in Washington.Brendan Buck, the press secretary for Republican House speaker John Boehner, tweeted: "Well, that'll be fun. A new DHS Secretary in the middle of the immigration debate."Napolitano
said she had been honoured to work for
Obama during such an "important chapter" for the country."We have worked together to minimize threats of all kinds to the American public," she said."The department has improved the safety of travelers; implemented
smart steps that make our immigration system more fair and focused while deploying record resources to protect our nation's borders; worked with states to build resiliency and make our nation's emergency and disaster response capabilities more robust; and partnered with the private sector to improve our cybersecurity."Obama administrationUS national securityUS domestic policyUnited StatesBarack ObamaUS educationPaul Lewisguardian.co.uk
© 2013 Guardian News and Media Limited or its affiliated companies. All rights reserved. | Use of this content is subject to our Terms & Conditions | More Feeds Scott Graham's debut feature casts a spell with its portrait of cramped lives on a Scottish petrol-station forecourtScott Graham's debut feature is a hushed and haunting coming-of-age drama, pungently played out in the remote Scottish highlands, where the wind boings off the microphone and passing lorries set the crockery rattling. Chloe Pirrie plays the teenaged Shell, "like the petrol station", who tends to her jittery, reclusive father (Joseph Mawle) and the various lonesome drifters who pull into their forecourt.
Along the way, Graham
paints a sharp portrait of cramped lives in wide-open spaces and sexual desires that threaten to lose their bearings, bounding off in dangerous directions, surely destined to run aground. He keeps the tale on a
steady simmer right through to the closing moments, when it spits and sputters into melodrama. Until then, Shell casts a spell.Rating: 4/5DramaXan Brooksguardian.co.uk
© 2013 Guardian News and Media Limited or its affiliated companies.
All rights reserved.
| Use of this content is subject to our Terms & Conditions | More Feeds The NCAA stripped Oregon of a scholarship in each of the next two seasons and placed the program on probation for three years, opting against stiffer penalties like a bowl ban despite issuing a show-cause order against former coach Chip Kelly, who apologized to the school, its fans and it players. The bride is an actress; the groom is a playwright and teaches screen and playwriting to high school students. David Lynn of Britain and PGA Tour rookie Derek Ernst finished tied in regulation and headed into a sudden-death playoff in the Wells Fargo Championship at Quail Hollow in Charlotte, North Carolina on