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Statement: “It was just after midday in San Diego, California, when the disruption started. In the tower at the airport, air-traffic controllers peered at their monitors only to find that their system for tracking incoming planes was malfunctioning. At the Naval Medical Center, emergency pagers used for summoning doctors stopped working. Chaos threatened in the busy harbour, too, after the traffic-management system used for guiding boats failed. On the streets, people reaching for their cellphones found they had no signal and bank customers trying to withdraw cash from local ATMs were refused,” New Scientist magazine wrote March 6, 2011.

Determination: Misleading

Analysis: New Scientist, a magazine based in Great Britain, seemed to have uncovered a major incident in San Diego, one that received no local media attention at the time. According to the magazine, a global positioning system outage happened because the Navy accidentally jammed GPS signals in downtown San Diego.

The magazine uses the Jan. 22, 2007 incident to make a larger point about the fragility of the GPS signals used not only for car navigation but also in increasing numbers of everyday systems. “Some are worried that we are now leaning too heavily on a technology that can all too easily fail — and it doesn’t need a freak navy training exercise to cause havoc,” the New Scientist writes.

So did the incident actually happen? I contacted the port and the Federal Aviation Administration to ask about the problems it created. They said they had no idea what I was talking about. The Navy said it was mystified too. So I dug deeper.

The story of the San Diego incident appears to have first been made public by a Coast Guard navigation official at a GPS conference later in 2007. The official has since retired, but Gene Schlechte, a division chief at the Coast Guard Navigation Center, agreed to speak about the incident.

His account confirms that the Navy did accidentally jam the GPS system around downtown San Diego in January 2007. But the New Scientist story overstates its impact.

The air-traffic control system didn’t malfunction, for example. Schlechte provided a report that the FAA sent to the Coast Guard a day after the GPS incident. It says there was no disruption to air traffic control.

What about the prospect of “chaos” in the harbor, as New Scientist puts it? Coast Guard vessels did report a loss of GPS service, Schlechte said, but there was no widespread problem in the port.

And cell phones didn’t actually stop working. Schlechte said two cell phone network operators lost GPS signals from their cell towers downtown, but switched to other ways of synchronizing their services. “Neither cell phone network operator reported any loss of cell service to their customers,” Schlechte said.

We couldn’t rule out some of the impacts described in the story. Like whether ATMs shut down. That’s unclear. Schlechte couldn’t confirm whether they did or not.

It is possible, however, that the paging system at the naval hospital went down, as the article states. The jamming did shut down a paging company’s services for about 30 minutes, Schlechte said. He declined to identify the company.

In regard to the conflicts between his article and the Coast Guard’s version, article author David Hambling said his sources’ information conflicts with some of Schlechte’s statements. However, the Coast Guard is the “definite authority … so clearly they have the final say,” he said.

Hambling added that “the level of secrecy around this gives me pause for thought, though. Was the threat from GPS jamming overplayed for some reason, or is it now being downplayed? We have no way of telling.”

To recap: The Navy did indeed accidentally jam GPS signals in the downtown area in January 2007. According to accounts and reports provided by the Coast Guard, the New Scientist article exaggerated the incident’s impact, incorrectly reporting that air traffic control and cell phones were disrupted and that chaos erupted in San Diego Bay.

Overall, the tone of the article suggests that the GPS outage had an extensive impact on San Diego. The Coast Guard’s version of the incident suggests otherwise. For that reason, the story is Misleading, because it’s exaggerated.

If you disagree with our determination or analysis, please express your thoughts in the comments section of this blog post. Explain your reasoning.

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Randy Dotinga

Randy Dotinga is a freelance contributor to Voice of San Diego. Please contact him directly at

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