GPS jammers are somewhat overrated.  Iraq used at least four GPS jammers in an attempt to reduce the accuracy of JDAM guided smart bombs. With GPS guidance, JDAM will land within 40 feet of the target. With GPS jammed, it will land within 100 feet. The Iraqi jammers were quickly located and destroyed. While the GPS satellites signal is compared to a 25 watt light bulb viewed from a distance of 17,000 kilometers, that only describes the civilian signal. GPS uses a special military signal that is a thousand times stronger than the civilian one. There are more announced (like G-STAR) and secret anti-jamming technologies being put into service in the next year. There will be more attempts at GPS jamming in future conflicts, but the ability to do that successfully has now been revealed to be more potential than performance.