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Singapore’s $300-Million Air-Traffic Automation System Unveiled

As the plane carrying your correspondent from Hong Kong to Singapore started its descent to the Changi airport, the worlds fifth busiest, it started flying circles. Shortly afterwards, the captain explained that multiple aircrafts were on holding pattern and the queue was changing quickly. That, I was assured, had nothing to do with the official launch of the airports new US $300-million air traffic control system. Instead, the delay was due to the final day of the Chinese Lunar New Year holidays, and it probably would have been a lot worse without the new system.

Soft launched in October and jointly developed by French engineering firm Thales and Singapores aviation authorities, LORADS III is the latest iteration of a proven air traffic control system called TopSky-ATC. And its main strength is that it gives controllers better information, faster. 

To understand how, you have to remember that air traffic control actions in many places are still done by recording flight dataairplane call signs, speed, bearing, altitude, and other informationon strips of paper, and instructions. 

Like all modern ATC systems, LORADS III does without paper strips. Thats all been digitized, but Thales is looking at doing without strips altogether, paper or digital: the ideas is to move towards much richer labels and a management system that give at a glance a clearer, more complete picture of the congestion status of a given airspace.

Hovering the mouse over each track symbol allows the controller to see a plethora of data and issue commands that can get relayed to the aircraft via satellite. The new commands pop up in the on board navigation and communication instruments  and the pilot can decide whether to implement it or not. (They usually do, unless they have a good reason not to—they are too heavy to climb to a higher level or they are cruising already at their fastest, for example.)

Usually these commands are radioed in when in radio range and its fair to assume they still will be for some time but this sort of command-by-text-messaging would reduce controllers workload, according to Thales. This will also reduce the radio chatter, which at busy airports and on certain frequencies is up to capacity and represents a bottleneck for more efficient operations. For control of the skies over oceans its even more important. Long distance communications between ground controllers and aircrafts goes over HF radio, notoriously finicky and with a range that depends on weather conditions. Controllers can instead transfer small amounts of data via satellite or by HF or VHF radios, because, as anybody trying to make a call on a busy cell network has noticed, its much easier to slip a small text message through, than place a voice call. 

The commands and subsequent execution, together with key flight data are stored in a central system called the Flight Data Processor, which calculates in real time everything pertaining to the position and trajectory of each aircraft. Every work station is connected to it, so all controllers have an up-to-date view of whos going where and how fast. 

 “It a simple change, but its also very complicated, because there are more than a hundred positions in the Singaporean Traffic Center and training facilities, says Andrew Nabarro, business development manager for air operations at Thales. Now, each person can have access to customized information at different times.

The first step, though, is knowing where aircraft are. This involves both active and passive sensing. Airplanes beam out their name, location, route and whatnot through an ADS-B feed, or automatic dependent surveillance broadcast. ADS-B is a type of transponder that beams out the GPS position of the aircrafts about once per second. 

Theres radar too, of which there are two kinds: primary radar sends out a burst of energy and waits for a reflection from an aircraft. Secondary radar instead interrogates a receiver placed aboard the airplane, which in turns answers with its identifier and altitude. Secondary radar has a longer range, about 250 nautical mile (460 kilometers); primary reaches less than half that distance.  But primary works with any type of aircraft whether or not theyve been equipped with the transmitter needed for secondary radar.

LORADS III has to make sense of all those signals to come up with a single set of information about the aircraft above Singapore. Thalesproprietary solution, called Multi Sensor Track Processing, takes all the different tracks from all the different radar, many ADS-B receivers, many wide area multilateration receivers, which is another type of surveillance, and turn it all up and says of all the sensors that we have, this is the actual position of the aircraft,says Nabarro.

Most air-traffic control systems are customized to manage a particular type of airspace; there are approach airspaces (think the area above and around a major airport) and en route ones (the skies of the North Atlantic, through which the bulk of Europe to U.S. traffic flies). Singapore, by virtue of its position in the middle of the Kangaroo routeconnecting the UK and Europe to Australia and several South East Asian countries, happens to need a system that can do both. The portion of sky under Singapores control covers an area of three quarters of a million square kilometers and its controllers preside over 220 000 annual movements. 

As the deluge of flights approaches for arrival at Singapore, the systems Arrival Manager kicks in. So instead of having a human being trying to sequence a whole bunch of airplane coming from all sorts of directions, at different speeds and altitude, the system will calculate the best sequence, says Nabarro. Here, bestmeans the sequence that gives the least amount of holding time for everybody.

Holding costs airlines thousands of dollars per flight in wasted fuel. Usually, airplanes begin their descents from cruise level when they are about a hundred nautical miles (185 kilometers) from the airport, but they only learn of congestion as they get closer and reach a much lower altitude. At low altitudes, jet engines are much less efficient. With the Arrival Manager, controllers are able to tell approaching but still cruising airplanes to slow down or speed up a bit in order to sequence them in a way that reduces low-altitude holding. The order can, of course, be changed manually and the system will then recalculate the best sequence, showing the relevant controller what commands must be sent to which aircraft, in order to minimize disruptions to the flow of approaches. 

But whats good software, without the ability to back all the data up? The main system has a dual, fully redundant set of servers that make the Changi control room fail safe; controllers can switch from one to the other simply pressing a button. While this has been implemented before, Singapore officials wanted another layer of safety: at a neighboring training facility, theres a replica of the control room with yet another set of dual servers. This second set runs simulations for training of new controllers, but with minimal software tweaking it could be transformed into a fully autonomous back up control room, if anything catastrophic were to happen to main one. The two locations are a few kilometers apart, providing an added layer of strategic safety, as well.

Laser Link to Moon Trumped NASA and MIT Engineers’ Expectations

In October of last year, a team from NASA and MIT’s Lincoln Laboratory made space communications history by beaming data, via laser, at speeds reaching 622 megabits per second, to Earth from a spacecraft orbiting the moon. Radio-frequency systems used for space communications today are usually tens of times slower.

NASA and Lincoln Lab engineers tested this first-ever two-way laser link between the moon and the earth, dubbed the Lunar Laser Communication Demonstration (LLCD), for about a month. And, as it turns out, the test was underwhelming: no jaw-clenching, fingernail-biting, arm-clutching moments. In other words, an engineer’s dream.

“It worked like gangbusters,” says Don Boroson, who led the LLCD design team at Lincoln Lab, and presented the demo’s results at the SPIE Photonics West conference on 3 February.

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China's "Jade Rabbit" Moon Rover Awakens With Same Problems

China's lunar rover is not ready to say "good night moon" just yet. The rover, called Jade Rabbit, has awakened from the long lunar night—but only after Chinese state media reported of its death. This gives Chinese mission controllers another chance to figure out the rover malfunction that first led to fears of its untimely demise.

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What You Need to Know About Mt. Gox and the Bitcoin Software Flaw

Here's what a terrible week looks like in the world of Bitcoin: Two of the most trafficked Bitcoin exchanges, Mt. Gox and Bitstamp, temporarily halt trading and suspend bitcoin withdrawals in the midst of a distributed denial of service attack (DDoS). On exchanges that are still open for business, the value of the currency takes a brutal, sudden hit and then continues to tumble. Bitcoin users notice strange errors in their wallet balances after making routine transactions. Rumor spreads that the Bitcoin protocol is critically flawed. And where rumor is lacking, conspiracy theories abound.

All this, and it's barely Thursday.

Some of it is true. Some of it is half true. Some of it is completely false. Here is what's really going on.

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National Ignition Facility Achieves Record Energies

Big fusion milestones are rare things. But a team based at the National Ignition Facility (NIF) says they've reached one. For the first time, they've been able to get their deuterium-tritium fuel to fuse so that it produces more energy than was deposited into it.

The researchers are quick to note they've not achieved the long-awaited goal of ignition—a self-sustaining fusion reaction that produces more energy than what is sent into the experiment. Most of the 1.8 megajoules of energy in the facility's lasers is still lost in the effort to achieve the temperatures and pressures needed to get fusion started. This process involves hitting the inside of a cylindrical gold container with 192 lasers in order to produce X-rays. That radiation then heats and blasts away the outer layer of a spherical capsule suspended at the center of the cylinder. The reaction force sends the remainder of this target inwards, compressing some 170 micrograms of frozen deuterium-tritium fuel at the center.

Today only about 1 percent of the energy poured into the cylinder actually winds up in the fuel. Still, team leader Omar Hurricane told reporters in a press briefing on Monday that this latest milestone is "kind of a major turning point in a lot of our minds." The results are published this week in a paper in Nature(A similar announcement was made in August of last year, when some 8000 joules of energy were released in the form of neutrons. In this paper, the team reports yields as high as 17 000 joules.)

The team is also encouraged by evidence of what's called alpha particle heating—a process by which helium atoms created in fusion reactions deposit their energy into the fuel instead of escaping. This "bootstrapping" process—using fusion to create more fusion—is what will be needed to ultimately get the yield up to ignition levels.

NIF has been taking a more research-oriented approach to fusion since late 2012, when the facility wrapped up the National Ignition Campaign, aimed at achieving ignition in just two years. The laser shots fired during that campaign tended to have what's called a "low-foot"—the laser power began at low power and was then ramped up. This approach made target compression fairly easy, but it created instabilities and asymmetries that sap power out of the compression process. "Those early implosions tended to rip themselves apart," Hurricane told reporters on Monday.

He and his colleagues took what might be called a step back, experimenting with "high-foot" pulses. These laser shots start out at high power, which quickly raises the temperature of the capsule. This approach makes capsule shells harder to compress, but also increases the speed at which layers are blasted off the capsule, which helps stop instabilities from growing. "Those two effects act together to make it more stable," Hurricane said. 

The team is now exploring ways to increase the yield even further with adjustments to capsule design.

In terms of yield, NIF is still behind the magnetic confinement approach pursued by experiments such as the Joint European Torus (which currently holds the record), Steven Cowley, director of the UK's Culham Centre for Fusion Energy, told IEEE Spectrum in an email. But he adds both approaches are now finally, after 60 years, getting "close" to controlled fusion. "We must keep at it."

A Hearing Device With No Stigmatizing External Hardware

Cochlear implants are among the most successful hearing devices out there. They have been around for about 30 years and more than 220 000 people worldwide enjoy restored hearing because of them. But they require clunky hardware mounted onto the skull and behind the ear that limit their use in the shower and often stigmatize the people who wear them. But this week, a team of scientists will present a new, alternative design that eliminates all the external hardware of the traditional cochlear implant and allows it to be charged wirelessly with a smartphone. 

The key to the new design is an implantable low-power signal-processing chip developed by Anantha Chandrakasan and his colleagues at MIT in Cambridge, Mass. The team cleverly integrated its microchip with an implantable piezoelectric sensor, and has tested the system in a human cadaveric ear. They will present their paper this week at the International Solid-State Circuits Conference in San Francisco. (Chandrakasan is the same researcher who in 2012 demonstrated how to harvest energy from the middle ear.)

Chandrakasan's new device works like this: A piezoelectric sensor mounted at the umbo in the middle ear picks up sound. That signal, a measure of the sound-induced motion of the umbo, travels to the microchip implanted elsewhere in the ear, where it is conditioned, digitized and processed. The chip then converts the signal to electrical waveforms and pumps them to electrodes implanted in another part of the ear called the cochlea. The waveforms received by the electrodes stimulate auditory nerve fibers and make the sound audible to the user. The device can be charged wirelessly in just a couple of minutes using a mobile phone and special adapter.

The design would be a huge improvement over existing cochlear implants, which require the user to wear the external components—mainly for power—at all times.

Researchers elsewhere have been working on alternatives to today's cochlear implants as well. In 2012, Darrin Young at the University of Utah designed a MEMS-accelerometer-based middle ear microphone that also moves all the external components of the cochlear implant inside the body. But Young's sensor draws a few milliwatts of power—more than MIT's design. An implanted rechargeable battery will be required. Young says his team is working on improving the prototype. "We are expecting a further power reduction by at least a factor of 20. This will bring down the power below 100uW," he said.

Further work, particularly on the sensor component, is needed before MIT's chip is ready to be implanted in a human. The geometry of the sensor still needs to be optimized, as does the method of stabilization, says Konstantina Stankovic at Harvard Medical School, who collaborated on the project. "A tricky thing with the implantable sensors has been stable placement and avoidance of sensing bodily noise," she says.

Now on Google Earth: 150 Years of Global Temperature Data

The Climate Research Unit (CRU) of the University of East Anglia has made its worldwide historical record of over-land temperature data available as an overlay on Google Earth. (And non-KML, comma-delimited temperature data files, along with many other kinds of climate records, are available at http://www.cru.uea.ac.uk/data.) The CRU Temperature database, version 4 (CRUTEM4) includes information from some 6000 weather stations, with some time series reaching back to 1850.

The big new data sets may leave some people cold. Others, though, look forward to poring over gigabytes of new information with the glee of Scrooge McDuck diving into a pile of gold doubloons.

The CRUTEM4 Google Earth data is provided in Keyhole Markup Language (KML is named after its developer, Keyhole, Inc., which was acquired by Google). The CRUTEM4 KML schema divides the Earth’s land surface into 780 grid boxes, each 5 degrees latitude by 5 degrees longitude. Users can click any box to see temperature information for that area: options include year-by-year variations (called “anomalies”) from historical means, tracing changes in annual and seasonal average temperature. By default, these consolidated data are “homogenized”—processed to emphasize variations above and below the mean, without noting what that mean temperature might be. The un-normalized temperature data are, however, available at a deeper level: users can drill down to see annual and seasonal temperature data for each individual weather station—like, for example, the station at Krasnaya Polyana, in the mountains near Sochi, Russia, where many Winter Olympics events are now underway.

CRUTEM’s curators, the University of East Anglia’s T.J. Osborn and P.D. Jones, describe CRUTEM and the Google Earth expansion in an Earth Systems Science Data paper. They go into detail on the mechanics and rationale of homogenization—sometimes extensive adjustments needed to compensate for missing data, suspect data, and systematic variations (e.g., changing the method of temperature measurement or moving the measuring station to a different altitude).

CRUTEM4 is the latest in a series of CRUTEM incarnations dating back to 1986. This release, offering increased transparency of the data, may be of particular interest because Osborn and Jones were among the climate researchers embroiled in controversy following the release of stolen CRU e-mails in 2009 and 2011. Widespread accusations, surfacing first among bloggers who resist the idea of climate change, charged climatologists at CRU and elsewhere with trying to derail the peer review process and stifle opposing views. Subsequent investigations by University of East Anglia, Pennsylvania State University, and the House of Commons, among others, largely exonerated the “pro-warming” researchers of wrongdoing, but the brouhaha did succeed in tarnishing reputations of climatologists whose work indicates global warming, and burnishing the rhetoric, if not the substance, of climate-change deniers.

Though there had been speculation that the e-mails had been stolen by a disaffected person inside the University of East Anglia, British police concluded in July 2012, that “the hack was the work of ‘sophisticated’ outsiders, not a whistleblower at the university,” according to The Guardian. Authorities nonetheless closed the case, because, they said, they did “not have a realistic prospect of identifying the offender or offenders and launching criminal proceedings within the time constraints imposed by law.” 

D-Wave's Quantum Computing Claim Disputed Again

The strongest scientific evidence for D-Wave's claim to have built commercial quantum computers just got weaker. A new paper finds that classical computing can explain the performance patterns of D-Wave's machines just as well as quantum computing can—a result that undermines crucial support for D-Wave's claim from a previous study.

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Bitcoiners Destroy Their iPhones After Apple Removes Wallet From App Store

On Wednesday, Apple removed the Blockchain wallet app, the only remaining app that could be used to make Bitcoin payments on the iOS platform, from its App Store. And Bitcoiners are pissed off. How pissed off? One particular Apple customer was so angry that he blasted his iPhone to smithereens with a rifle. Luckily for us, he filmed himself doing it.

He did, however, have more to gain than a rush of sublime catharsis and 15 minutes of YouTube fame. Ryan, as he identifies himself in the video, shot up his phone in a spirit of protest, but only after a Reddit user besought enraged Bitcoiners to publicly destroy their iOS devices with the promise that he would send them new, Nexus 5 smartphones in return. The user, "round-peg," promised one replacement phone for each 100 "upvotes" he got on the Reddit post, but limited it to six phones after a deluge of attention.

It seems that this was the last straw for many iPhone-toting Bitcoin users. The Blockchain app was only the most recent Bitcoin app to get pitched from the Apple marketplace. Last November, it shut down another app which allowed users to interface with Coinbase accounts (Coinbase functions both as a Bitcoin wallet and a Bitcoin exchange.) In December, it booted a comparable app designed by CoinJar (though it's still available to Australian customers). And last month, Apple forced Gliph to remove Bitcoin transaction features from its secure messaging app. All of these apps are still available in the Google Play Store for use on Android phones, such as the Nexus 5 (except CoinJar, which says it's still working on it).

Apple has not made a public statement about why it's coming down so hard on Bitcoin. And according to the San Francisco Chronicle, company representatives declined to comment about this latest decision. But the snubbed app designers are coming up with their own theories. 

In a blog post yesterday, Blockchain went on the offensive, writing:

These actions by Apple once again demonstrate the anti-competitive and capricious nature of the App Store policies that are clearly focused on preserving Apple's monopoly on payments rather than based on any consideration of the needs and desires of their users.

Tim Cook, CEO of Apple, dropped some less than subtle hints to Time Magazine last week, suggesting that the company would have some kind of mobile payments platform to offer with the next iphone. It's not difficult to see how a global, frictionless, digital currency might get in the way of those plans. 

But it's also important to keep in mind that Bitcoin is going through some serious growing pains right now. These are Bitcoin's awkward, teen years, when it just keeps rolling with the wrong kids and getting into trouble. In the last six months, the biggest news stories about Bitcoin have involved the arrests of an alleged drug kingpin and the twenty-something millionaire that may or may not have been laundering money for his customers. And it's still anyone's guess as to how governments will choose to regulate Bitcoin, or even how they will define it. So, it's not inconceivable that Apple, a notoriously skittish company, might shy away from Bitcoin for the moment.

This seemed to be the impression that CoinJar got from its dealings with Apple. After having its app pulled, it explained to its users:

Before you start DDOSing and trolling, Apple have done nothing wrong in this situation, they are just managing their own legal liability. We have had amicable discussions with them and hope they will support us in the future, when they have a more clear view of Bitcoin's place in their regulatory landscape.

Regardless of how angry people are about this decision, the reality is that Bitcoin is still so small that it can't yet muster an impressive public outcry. Of course, there's already a petition started, but I'm guessing that Apple has made up its mind on this one, and it's not likely to change course, even if people start shooting their phones with canons tomorrow. I say, Bitcoiners, do what you do best, and opt out!  

Lockheed Martin Shows Off High-Power Fiber Laser Weapon

The US military dreams of a small but powerful laser weapon that can zap enemy rockets and drones from a safe distance. But weapons that have been demonstrated so far have been too big and heavy to fit on-board humvees and fighter jets. They’re also notoriously difficult to cool.

So key players in the defense industry have turned to fiber lasers to make the military's dream a reality.

Lockheed Martin said last week that it has demonstrated a 30kW fiber laser. In May 2013, Lockheed was able to shoot down rockets with a portable 10kW fiber laser from about 1.5 km. The company claims in a press release that this latest achievement is “the highest power ever documented while retaining beam quality and electrical efficiency” and that the fiber laser consumes half the power of more conventional solid-state laser.

MBDA Systems, Raytheon, and Northrop Grumman have all reported their own high-power fiber laser weapon feats in the past couple years. In October 2012, MBDA Systems’ German subsidiary used its 40kW system to shoot down airborne artillery from a distance of 2  km. The 40kW system was built with four 10kW sources provided by industrial fiber laser maker IPG Photonics. Northrop Grumman is also busy developing high-power fiber lasers through various military contracts, including the Army’s Robust Electric Laser Initiative.

Fiber lasers use a special type of optical fiber as the light-emitting material, as opposed to the neodymium-doped crystals used in conventional solid-state lasers. Because the fiber can be coiled, developers can pack more power into a compact system. They can  be up to two times more efficient than traditional solid-state lasers, and the larger surface-to-volume ratio of the fibers makes them much easier to cool.

They do have a power limitation, though. Single-fiber lasers can’t achieve high power and beam quality. So most high-power systems, including Lockheed Martin's, combine beams from multiple fiber laser beam modules into a single high-quality beam. Some believe that the military's 100-kW benchmark power output for a laser weapon could be challenging to reach with fiber lasers.

That benchmark came about from an Army project from over a decade ago, which established that destroying a moving target from a kilometer or two away requires 100kW, mainly to overcome the spreading of the laser beam. But lasers have come a long way since, and as IEEE Spectrum outlines in the article "Ray Guns Get Real", some experts question the necessity of a 100-kW laser system. The recent demonstrations mentioned above certainly show that lasers delivering tens of kilowatts could be of use.

The real test for fiber lasers could come later this year, when the US Navy installs its laser weapon system on the USS Ponce transport ship, two years ahead of schedule. The Navy showed in 2010 that its laser weapon system, developed by Raytheon, could shoot down unmanned aerial vehicles.

Photo: U.S. Navy

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