[Dan(9698)]

The GPS satelites are not 21,000 miles up.

They are low earth orbit, and the antenna is on the back of the bomb, with directional coverage.

The bomb looks up, not down and so the jammer would have to be reletively powerful.

[PokeyJoe]

I understand that the JDAM kits use a spread spectrum encrypted relay via a data link/military channel. VERY hard to jam - so not only would it have to be a powerful jammer, it would have to be very LOUD (spectrum blocker).

I also understand that JDAM kits use a backup inertial guided GPS system (meaning that the bomb has a memory of where it is and calculates where it wants to go if it loses GPS signal).

I wouldn't want to be the Iraqi beta testor for the Russian Jammers.

I have a feeling that the Iraqi's may have deployed them to high value targets, not knowing that they actually helped us locate where we should place precision munitions because of the GPS feedback. =)