The South Koreans believe their friendly neighbors to the north have jammed the Global Positioning Systems on hundreds of airliners flying in and out of South Korea’s major airports in recent days. It could be a typical North Korean tactic: come up with a low-cost way to cause trouble, especially one that’s difficult to trace. Luckily, today’s planes have other systems that can get them safely from Point A to Point B.
Last month, Pyongyang ratcheted up its standard provocative rhetoric to new levels, threatening to turn the government in Seoul “to ashes in three or four minutes” through “unprecedented peculiar means and methods.” The failure of a major missile test and rumbles of an impending nuclear-weapons test has further unsettled the peninsula. Could jamming its neighbor’s GPS be part of NoKo’s “peculiar means”?
Luckily, the U.S. Air Force – which operates the system – knows all about such challenges.
“GPS’ signal is a very weak spread-spectrum signal, and it is not difficult to jam,” Air Force General William Shelton, chief of the Air Force Space Command, told reporters recently. “And it is not difficult to get a GPS jammer. In fact you can buy one online. Illegally, but you can buy one online.”
The Air Force launched the first GPS satellite in 1989. Its full constellation of 24 was in place by 1994. Linked electronically to one another, they provide precise time and location data to anyone, anywhere in the world, on devices ranging from cell phones to cameras to ICBMs. But their weak signals can be overwhelmed with electronic jamming.
That’s why, Shelton told Battleland, the Air Force is boosting the power of the signals transmitted by new-generation GPS satellites to protect them from jamming. It’s also altering their antennas to reduce their vulnerability to such interference.
The small GPS jammers available online “are very hard to find and target,” Shelton said. “We’re starting to see even criminal elements use GPS jamming to cover their tracks.”
We don’t think Shelton meant to imply Kim Jong-un and his junta of huge-hatted generals constitute a “criminal element,” but he plainly frets about such gear falling into the wrong hands. His biggest concern is powerful jammers that could shield enemy missile systems or other valuable sites from air attack by GPS-guided weapons.
“The game afoot here is to continue to drive a no-kidding adversary — not the criminal element, but a no-kidding adversary — drive them to higher and higher powers of their jammers,” Shelton said. “Once you get to a significant power level, those are called `targets.’”