There’s No Backup System if GPS Fails

This should be troubling to anyone paying attention to anything else other than their favorite sports team. Reason being: The GPS infrastructure is already out-dated and crumbling as we speak. The system used to to guide troop movements, assist with logistics support and situational awareness, guide missiles and bombs, and synchronize communications networks is due to collapse by 2020 if nothing is done about it. Without it, America would face a choice: Be crippled for years until a backup system takes place, or become dependent on Russia’s GLONASS system, or even China’s BeiDou navigation satellite system. If this seems far fetched, ask those in NASA who have to hitch rides on Russian rockets to reach space nowadays at a very high cost — or those in the satellite launching industry who rely on Russian rockets because America doesn’t supply them anymore.


In only took 13 millionths of a second to cause a whole lot of problems.

Last January, as the U.S. Air Force was taking one satellite in the country’s constellation of GPS satellites offline, an incorrect time was accidentally uploaded to several others, making them out of sync by less time than it takes for the sound of a gunshot to leave the chamber.

The minute error disrupted GPS-dependent timing equipment around the world for more than 12 hours. While the problem went unnoticed by many people thanks to short-term backup systems, panicked engineers in Europe called equipment makers to help resolve things before global telecommunications networks began to fail. In parts of the U.S and Canada, police, fire and EMS radio equipment stopped functioning. BBC digital radio was out for two days in many areas, and the anomaly was even detected in electrical power grids.

Despite its name, the Global Positioning System is not about maps; it’s about time. Each satellite in the constellation (24 are needed, plus the U.S. has several spares) has multiple atomic clocks on board, synchronized with each other and to Coordinated Universal Time—the time standard used across the world—down to the nanosecond.

The satellites continually broadcast their time and position information down to Earth, where GPS receivers in equipment from iPhones to automated tractors acquire signals and use the minuscule differences in their arrival time to determine an exact position.

* * *

There are plenty of reasons GPS could fail.

Intentional attack is one, as emphasized by a declassified 2012 risk estimate by the Homeland Security Department. One of the system’s most basic problems is its signals are weak enough to be easily obstructed. Truckers with cheap jamming devices designed to elude employer tracking have unintentionally interfered with airport systems; criminals thwarting GPS tags on stolen goods in shipping containers have accidentally shut down port operations.

On a grander scale, North Korea has tormented South Korea with waves of jamming attacks. (Jamming devices are now illegal in the U.S., but not difficult to obtain illicitly.)

* * *

So far, mitigating the loss of GPS signals has involved two approaches. One is interoperability with other global navigation satellite systems like Russia’s GLONASS (which also failed due to a ground control error in 2014) or the European and Chinese systems, both of which are expected to be up by 2020. The other is better clocks, says Lombardi, the NIST metrologist, who’s published numerous articles on the topic.

“The typical cell tower clock has an oscillator similar to that of a wristwatch,” he says, “and can drift out of tolerance in minutes without a signal.”

How long a clock can maintain time on its own, called “holdover,” also affects electrical grids, many of which rely on GPS-dependent devices called synchrophasors used to precisely regulate current flow, as well as help locate faults in the network. A lack of such timing technology was the reason it took some Canadian technicians three months to locate failures after the infamous blackout of 2003.

The bulk of a more promising, comprehensive backup system already exists, right here on the ground. After the sextant but before GPS, navigators around the world used Long Range Aids to Navigation, or “LORAN,” a terrestrial system of transmitters and receiving equipment first developed during WWII.

If adopted, “Enhanced” LORAN, or eLoran, could provide positioning accuracy comparable to GPS. Broadcast at hundreds of thousands of watts, the signal is virtually un-jammable, and unlike GPS, can even be received indoors, underwater, and in urban or natural canyons. It also turns out that eLoran can provide a UTC time signal with sub-microsecond time resolution across a large geographical area.

After this year’s satellite error, many European officials who had previously followed America’s reluctance to adopt eLoran stepped up development. Meanwhile, pressure from Garamendi, who argued in his address that “without an eLoran system in place ASAP, this country is in serious, serious jeopardy,” prompted a letter to him from the deputy secretaries of Defense and Transportation informing that the PNT Executive Committee has agreed that an eLoran-based timing network “could provide a near term solution” (if private entities bore some of the cost) while they “continue [their] efforts to prescribe a complete set of requirements necessary to support a full complementary PNT capability for the nation.”

In other words, it seems: federal time.

* * *

On July 23, 2012, a billion-ton cloud of electrified gases blasted off the far side of the sun at over 6 million miles per hour. According to professor Daniel Baker at University of Colorado, this coronal mass ejection “was in all respects at least as strong as the 1859 Carrington Event,” referring to the strongest solar storm ever recorded, which set fire to telegraph stations and caused auroras down to Cuba. As was widely reported two years ago, if the 2012 CME had occurred one week later, it would have hit Earth.

Space Katrina would be biblically catastrophic. Power could be out for years while electrical transformers were repaired, if the resources are even available to do so.

In 2014, physicist from San Diego calculated the likelihood of a Carrington-level event in the next decade. The odds he came up with were 12 percent.

Full article: There’s No Backup System if GPS Fails (NextGov)

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