GPS Basics
• Made up of a constellation of 27 satellites
• Each of these satellites are about 12,000 miles from the Earth
• Set up so that at any given time, at least four satellites can be picked up for navigation
• Originally developed by the U.S. military, but quickly branched out into civilian use
Communications
• Two things need to be communicated• 1. The locations of at least three satellites above
the receiver.• 2. The distance between the receiver and each of
the satellites.
• Sent in form of radio waves, traveling at the speed of light
• Waves are high in frequency, but low in power.
Distances
• Distances are found by measuring the amount of time for the signal to travel from satellite to receiver.
• It measures the time delay of pseudo-random code. NAVSTAR
Civilian Jammers
• An article in hacker mag Phrack reported how to make a low-cost GPS jammer.
• The materials for this product could be easily obtained from electronics stores.
• “The onslaught of cheap GPS-based navigation (or hidden tracking devices) has made it necessary for the average citizen to take up the fine art of electronic warfare."
-Phrack Magazine
D.O.D.
• This article made a big enough impact that the Defense personnel even issued statements.
• Not a current threat to aircraft or military functions.
• Can affect commercial use.
The “But”
• Richard Langley, a GPS expert and professor of geodesy at the University of New Brunswick in Fredericton, New Brunswick said that these jammers would not be effective against aircraft from the ground.
• BUT if used onboard a plane, it would increase the range/effectiveness of the jammer.
Why shouldn’t it affect military operations?
• Civilian GPS operates at 1575.42 MHz
• Military GPS operates at 1227.6 MHz.
--Statements by Phrack Magazine
James Hasik
• Consultant/author of The Precision Revolution: GPS and the Future of Aerial Warfare disagrees with Phrack.
• Says the Phrack jammer is targeted at GPS signal, known as “C/A code.”
• Could be a threat to military GPS because they must get C/A signal before getting military, “P(Y) code.”
The Pentagon
• They don’t “at the moment” view these jammers to be a threat.
• Pentagon GPS experts do not believe that they will affect flight safety for commercial operations.
Iraqi Military Jammers
• There have been reports that the Iraqis have acquired 200 jammers from Russian firms.
• These would instantly cause civilian casualties.
Will they affect U.S. operations?
• Some say yes, but the fact is that the U.S. has anti-jamming technology.
• We surely have other things to combat these jammers. Odds are it’s basic anti-jammers. Then I started thinking, maybe it’s something really cool that I don’t even know about yet.
Is the U.S. worried about these jammers?
• NO!
• The Iraqi jammers are literally broadcasting their locations.
• If we were worried about them, we could take them out with relative ease.
Tricks for Iraq
• There is one trick that the Iraqis could play with these jammers.
• They could put jammers on top of mosques and residential buildings.
• If we tried to attack the jammers, we would be taking the lives of civilians.
• This would also give the Iraqis propaganda to use against the U.S. since they wont win a military war.
• Can we handle this type of situation?• Of course…
Aviaconversiya Ltd.
• Reportedly is the Russian company which sold Iraq their 200 jammers.
• In March 2003, U.S. Army awarded about $200,000 in contracts to this company.
• We bought jammers in order to test their capabilities
How do we get around jammers?
• Boeing has developed anti-jamming technology.
• That was back in 1998. Imagine what we have now.
JDAM Tail Kits
• JDAM (Joint Direct Attack Munition)
• Use GPS and Inertial technology.
• May be more navigation systems in them that haven’t been made public.