lundi 30 juillet 2012

New Satellites Could Make GPS Harder to Jam

By Lorenzo Franceschi-Bicchierai

July 26, 2012 | 6:30 am |

Artist rendering of a GPS III Satellite. Illustration: Lockheed Martin

Without GPS, drones can’t fly, communications networks can’t function, and you don’t have a chance of figuring out how to get to your Aunt Sadie’s place in New Jersey. And right now, GPS is highly vulnerable because its weak signals are coming from an aging constellation of satellites.

Lockheed Martin, the nation’s biggest military contractor, thinks the next generation of GPS satellitesmight be able to fix all that. GPS III, as it’s known, is designed to improve the accuracy of the GPS signal and have better resistance to jamming. Also, it is meant to be compatible with its international alternatives like the European Galileo system or the Russian GLONASS system. Potentially, it will improve GPS’ accuracy and resistance to jamming — the deliberate or accidental transmission of radio signals that interfere with regular communications.

In 2008, Lockheed Martin was awarded a $1.4 billion contract to design and develop the system and to build the first two satellites of the new constellation; the first of those is set to be launched in 2014. In January the Air Force gave Lockheed a $238 million contract to produce two more satellites.

Eventually, the Air Force plans to purchase up to 32 satellites that will end up replacing the current constellation of aging GPS satellites. “GPS is really the gold standard internationally for PNT [Position Navigation and Timing],” says Scott Lindell, the director of strategy and business development at Lockheed Martin. “And [it] has become this ubiquitous global utility that everybody is using. Overtime the system needs to be replenished, the satellites on orbit age and at some point they stop working.”

Young satellites mean better satellites too. According to Lindell, GPS III will transmit signals eight times as powerful as the current ones, allowing them to have better resistance against jamming. If you think of GPS signals as voices in a noisy room, if you want to be heard, you need to talk louder. That’s basically what the new signals will do. With GPS III, “you can tolerate a lot more noise and still be heard,” Lindell tells Danger Room.

This improved anti-jamming capabilities will be available both for civilian and military users. “There’s better anti-jamming for everybody,” says Logan Scott, a GPS industry consultant. And not only the signals will be more powerful, there will be more signals too.
An engineer working on a GPS IIR-M satellite, a satellite that is currently operating on orbit. Photo courtesy of Lockheed Martin spokesman Michael Friedman.

“The mere fact of having more signals available to the civil user is a major improvement in potential security,” says Scott, who thinks that could be a potential solution to jamming or even spoofing incidents as a security-conscious GPS receiver — say, one mounted on a civilian drone — could turn to the other satellite signals when it receives one that it doesn’t recognize.

But the key is detecting and recognizing it, and that’s something that it’s not possible today with open, unencrypted and unauthenticated signals like the ones used by civilian GPS. Logan says it’s possible to create “marked” signals, so that receivers know they’re coming from the satellite instead of some malicious hacker with a spoofer. Problem is, marked signals are not part of GPS III, and it’s unclear when or if they will be adopted.

So is GPS III the answer to all GPS troubles? In a word, no. “It would still be vulnerable, it’s not enough,” says Scott, who thinks the system is still open to attack since there’s no backup in case you lose GPS. A radio navigation system called LORAN (LOng RAnge Navigation) was used as backup until January 2010, when it was discontinued by the Department of Homeland Security. Logan considers that a mistake. “LORAN should be re-instituted, if not for navigation at least for timing,” he says.

Lindell declined to comment on LORAN, saying Lockheed can’t comment on what are ultimately policy decisions for the U.S. government. Meanwhile, the U.S. Air Force has teamed up with Locata, an Australian start-up, to develop an alternative to GPS, at least in limited spaces. Instead of relying on satellites, Locata sets up its own network of Wi-Fi band signal stations, delivering more accurate location data. It’s an ideal solution for places where the reach of GPS signals is limited or completely unavailable.

According to Lindell, GPS III will have better accuracy too, which will make the use of GPS possible in hard-to-reach natural areas like canyons or cities, where transmissions are sometimes blocked by skyscrapers – the so-called “urban canyons.”

“If you can’t see four GPS satellites at one time right now, you will lose accuracy and you could lose the lock on the signal altogether,” Lindell tells Danger Room. “In the future you don’t have to see four GPS satellites,” because apart from the improved power and accuracy of GPS’ signals, an average user will be able to take advantage of other systems’ satellites. “That allows us to go through urban canyons and real natural canyons.

Lindell declined to estimate when the new constellation of satellites will be in place, saying it’s not only up to them. It will depend on the Air Force as well as other factors like the actual need for new satellites since the old ones are still functioning — for now

http://www.wired.com/dangerroom/2012/07/new-gps-sats/

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