Iraq and other potential adversaries may have the ability to jam global positioning system signals, but Air Force war planners of US are not too worried about the effect of jamming on precision munitions. In fact, it is a challenge they have been anticipating for a long time, and they are confident in their ability to overcome it.
GPS is a constellation of satellites that emit electronic signals while orbiting the Earth. A GPS receiver gathers the signals from multiple satellites overhead, then triangulates those signals to calculate its precise location. Those receivers can be hand-held or mounted in ships, aircraft, vehicles and precision guided munitions. The United States routinely installs GPS guidance packages in standard 500- 1,000- and 2,000-pound bombs to create the Joint Direct Attack Munitions. The JDAM typically strikes within 13 meters of its target. According to reports, Iraq has acquired several Russian-made transmitters capable of jamming the GPS signal.
In general terms, someone could “jam” a radio signal by transmitting a more powerful signal on the same frequency. Carter equates the practice with trying to listen to a conversation on the other side of the room while another person shouts in your face. While the tactic may seem easy to accomplish, Carter said he would not encourage anyone to take the job.
A GPS jammer is not a silver bullet to prevent precision bombardment, Carter said, because the Air Force has more than one way to put steel on target. Those include the inertial navigation system within the JDAM, its primary navigation system, which is fully capable of guiding the weapon to its target. The Air Force also employs laser- and optically-guided munitions, as well as free-falling bombs. The Air Force also is looking ahead to ensure future GPS satellites are more jam-resistant, beginning with the current crop of modified GPS IIRs. That power increase will provide some anti-jam capability, but Teets said the real improvement will come when the GPS III is introduced in about 10 years.
Source: Air Force News Washington
