Guide bomb makers to predict GPS jammers

　　The makers of precision-guided munitions no longer take it for granted that simple GPS guidance systems will always work on their own. Jammers and deception devices threaten the future battlefield; Manufacturers have noticed and responded to this threat.

　　The military and its industry partners have various means fielded and in development to ensure that bombs hit their targets, whether that means redundant targeting systems like seekers that target GPS jammers, laser-guidance systems, or camera-aided navigation.

　　The reality of the threat is no secret. In 2011, North Korea shielded South Korean GPS signals, reportedly using Russian-made jamming equipment capable of jamming guided weapons. That same year, Iran shot down and captured an RQ-170 Sentinel drone, boasting that it had faked GPS data to divert the drone to land in Iran.

　　In short, noise from jammers can overwhelm nearby GPS receivers, which rely on weak signals from distant satellites, and thus lose their actual GPS signal. If a precision-guided bomb loses its lock within a minute of its target, the result could be catastrophic.

　　All the classic threats are there - Iran, North Korea, China, Russia, and GPS. There is no magic bullet that can replace GPS.

　　Fifteen years ago, jammers were considered the most common and expensive equipment in the government or country. But now, low-cost, low-power jammers are everywhere, riding the wave of cheap, reliable consumer electronics like Wi-Fi routers and smartphones. Although the military GPS system is more flexible than the commercial system, there is no 100% guarantee, especially against high-power jammers.

　　A $25 Chinese-made jammer, found online, can block the GPS signal around a car, while a two- or three-watt jammer the size of a cigarette pack, available for a couple of hundred dollars, could envelop several city blocks.

　　In a sign of how common this is, in 2013, a New Jersey truck driver tried to hide his location from his boss by using a GPS jammers, and every time he drove by Newark Liberty International Airport, have inadvertently interfered with air traffic control.

　　"Anyone who wants it gets it," said James Haskell, a senior fellow at the Atlantic Council and author of Precision Revolution: The Future of GPS and Aviation Warfare.“Honestly, we could set up a GPS jammer in the basement real quick.”

　　So can the enemy. John Flint, the project manager of JDAM, a Boeing Weapon and Missile System, imagined such a battlefield scenario: the U.S. military encountered a series of low-cost jammers, which were used to conceal targets and protect them from American missiles.

　　Russian-backed separatists in Ukraine and their state sponsors have “very definitely“ been using advanced electronic warfare equipment, he said, and the Defense Department has been working to discern how effective these were in jamming command-and-control networks and GPS frequencies.

　　These technologies are spreading as widely as conventional guided munitions. So in the future, US Army and US Marine forces, and our allies that fight with us, are going to have to fight on a battlefield that is swept by precision-guided munitions, but also one that is swept by persistent and effective cyber and electronic warfare attacks.

　　Department had increased its space defense budget by $5 billion, with a portion dedicated to anti-jam capabilities on satellites and in user equipment.