[infowar.de] WSJ 26.03.03: U.S. Bombs GPS-Jamming Sites In Iraq, Possibly Sold By Russia

[Georg Schoefbaenker <schoefbaenker -! - aon - at>]

Infowar.de, http://userpage.fu-berlin.de/~bendrath/liste.html
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Wall Street Journal
March 26, 2003

U.S. Bombs GPS-Jamming Sites In Iraq, Possibly Sold By Russia

By Anne Marie Squeo, Staff Reporter Of The Wall Street Journal

Just days after the Bush administration accused Russia of selling equipment 
to Iraq that could interfere with satellite-guidance systems, U.S. military 
officials said they bombed six sites containing such devices.

Military officials have been concerned that Saddam Hussein's government 
would employ jammers against the U.S. Global Positioning System. The U.S. 
increasingly relies on the system for guiding weapons, tracking its forces 
and enabling individual pilots and soldiers to know exactly where they are. 
Inexpensive jammers, including hand-held devices, can be bought on the 
Internet, though Iraqi forces apparently were using bigger, 
more-sophisticated ones.

"We have noticed some attempts by the Iraqis to use a GPS-jamming system 
that they have procured from another nation," said Maj. Gen. Gene Renuart, 
the director of operations at U.S. Central Command in Qatar. He didn't 
mention Russia, which has denied U.S. allegations that it sold such 
equipment -- as well as antitank missiles and night-vision goggles -- to 
Iraqi forces.

Air strikes by allied pilots in recent days destroyed six jammers the U.S. 
was able to identify, Maj. Gen. Renuart said, adding that one of the sites 
was hit by a GPS-guided bomb. Gen. Richard Meyers, chairman of the U.S. 
Joint Chiefs of Staff, said he believes those were the only jammers 
deployed by the Iraqis.

While U.S. officials stressed that the jammers didn't affect GPS-reliant 
weapons or equipment, the timing of the U.S. complaint to Russia and the 
bombing raids suggest that they have caused problems, some military 
analysts said. "If the jamming equipment was powerful enough to locate and 
target, it probably had some effect on U.S. bombs," said Anthony Cordesman, 
a military analyst at the Center for Strategic and International Studies, a 
Washington think tank.

U.S. officials say the majority of their bombs and missiles have hit their 
targets, but some clearly have gone astray -- missiles have landed in both 
Iran and Turkey. Military officials declined to provide specifics about 
where the Iraqis had placed the jamming devices.

GPS satellites, conceived by the military during the 1970s, circle the 
globe twice a day, continuously beaming radio signals that provide timing 
and logistical information to anyone with a GPS receiver. But because the 
signal travels 11,000 miles to get to the Earth's surface, it is fairly 
weak, and thus can be easily interfered with, Air Force officials and GPS 
specialists say.

The current constellation of about 24 satellites emits two signals -- one 
dedicated to the military and another that has been made available to 
commercial users around the globe such as telecommunications and 
transportation companies. The military signal is configured so it is 
difficult to interrupt, but the commercial signal is used to "find" the 
military one.

To jam GPS-reliant equipment, a transmitter either would attempt to emit 
"interference" on the same frequency the GPS operates or use additional 
power to knock out a broader spectrum of frequency, GPS specialists say. 
This interference would target receivers of such signals, not the 
satellites themselves.

Military officials have refused to say if the GPS has been jammed in 
battle. But fixes have been developed to overcome the problem. For 
starters, the Air Force and Navy both have electronic-warfare aircraft that 
were altered in the 1990s to detect GPS jams, said James Hasik, co-author 
of "The Precision Revolution: GPS and the Future of Aerial Warfare." 
Military officials also upgraded Raytheon Co.'s Harm missile so it can home 
in on GPS-jamming emissions, Mr. Hasik added.

Also, the military has alternative systems that can minimize the effect 
GPS-jamming can have on a bomb. Joint Direct Attack Munitions, which pair a 
GPS-guidance kit with a gravity bomb, also have a separate 
inertial-navigation system that is used as a primary means for finding 
targets, says a spokesman for Boeing Co., which makes the JDAM. This allows 
the bomb to find its target even if it loses its GPS signal. Analysts 
suggest that could be one reason a GPS-aided weapon could make a direct hit 
on one of the Iraqi jammers, as U.S. military officials said.



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