On GPS guided munitions

http://www.armada.ch/03-3/article-full.cfm

“Russia’s Bazalt State Research and Production Enterprise is developing an add-on guidance kit based on an inertial navigational system plus a GPS/Glonass receiver. The MPK (Modul Planirovaniya i Korrekciyi) modular add-on kit installs guidance and navigational electronics, foldout wings and a single movable control surface to existing ‘dumb’ bombs such as the widely used Fab-500 M62. Flight tests have begun, Bazalt announced, in the summer of 2002.”

Just on the article’s title:

“Type the phrase “GPS jammer” into any Internet search engine, and you’ll find dozens of sites assuring you that anyone with a modest degree of hobbyist electronic construction skills can build a jammer able to disrupt the Global Positioning System, an essential navigation aid in modern combat. But as the Iraqi armed forces learned in March 2003, GPS isn’t so easy to knock out.”

Well, not really. To reference Journal of Electronic Defense:

The GPS jammers were acknowledged to be from the Russian Aviaconversia company:

The Russian Aviaconversia company is a small, private development and production company, founded in early 1990s and based in Moscow. Recently, it has specialized in the production of simple, portable GPS jammers. The company produces the jammers from commercially available parts, and the equipment is not listed as defense related by Russia, since it is not built according to Russian military standards. The Russian armed forces do not use any Aviaconversia products.

There’s your explanation.

The system produced by Aviaconversia has a power of 4W and is claimed by the company to be able to create deceptive jamming out to a range of 150-200 km. It works at frequencies of 1,577 MHz (civilian channel) and 1,230 MHz (military channel). Each unit weighs 8-10 kg. Aviaconversia Director Oleg Antonov told the Russian television program “Vedomosti” that GPS jammers numbering in the “tens” had been delivered to “countries in the region,” referring to the Middle East. While he wouldn’t rule out their subsequent resale to other countries, he stressed that the numbers involved were insufficient to pose a threat to the US military. Greg Martz, a spokesperson for Interstate Electronics Corp. (Anaheim, CA), a maker of anti-jam GPS equipment for the US military, told JED that the GPS-jamming systems in question are too small and have too low an effective radiated power for them to be effective against US GPS-guided weapons, calling them “really irrelevant.” Martz said, “My guess is maybe they could disrupt a small radio on the ground, but incoming ordnance? No.”