Are microwave ovens jamming GPS signals?

Military users relying on location and navigation information from the 24 Global Positioning System satellites "should be terrified" about the possibility of jamming, a top official of the U.S. Space Command warned.

Vice Adm. Herb Browne, deputy Spacecom commander, called development of GPS jammers "easy," adding that "the same technology that can be used to build microwave ovens can be used top build GPS jammers."

Browne, speaking last week on an information systems security panel at West 2000, sponsored by the Armed Forces Communications and Electronics Association and the U.S. Naval Institute, added, "GPS is very vulnerable and GPS jamming is a very important national security issue." The Air Force used GPS-guided smart bombs extensively in the Kosovo air campaign. GPS signals also have myriad civil uses, ranging from surveying to serving as the technological bedrock of the Federal Aviation Administration's next-generation air navigation system.

Rear Adm. Robert Nutwell, deputy assistant secretary of Defense for command, control, communications, information, surveillance and reconnaissance systems, said the Pentagon has reached an agreement on modernization of the GPS satellite constellation to help defeat jamming, with a White House announcement due this week. Nutwell said that modernization would include a new secure military code for those satellites scheduled for launch starting in 2003 and new higher-powered satellites starting in 2009. Both the new code and higher-power systems promise better jam resistance, he said.

One of the challenges DOD faces in modernizing GPS is that the current generation of GPS satellites is "lasting too long" in orbit, Nutwell said. Users of handheld receivers can defeat jamming of signals from the current generation of GPS satellites by "placing them in a hole in the ground," he said.