How man $$/round?

per: http://www.nationaldefensemagazine.org/issues/2002/Jun/Tamper.htm Excalibur rounds will cost $15,000 each. mmmmm.....

Don't we have copperheads? That and would the cost discourage their usage in practice and thus discourage their wartime use? Copperhead is probably more expensive though...

Yes, the copperhead was many years ahead of this. But the copperhead was a laser guided and there were many ways to defeat it. Actually nature, in the form of a sandstorm, did a good job on it's own. The latest shells are GPS guided. To defeat them you have to defeat GPS.

GPS shells only land on GPS coordinates; that is, they cannot "follow" objects. You can try traditional "bracketing" I would think. If you have a laser guided shell, can you move the laser to follow a moving target?

Excellent point. Some of the newer GPS systems (bombs and missiles) can be updated in flight, this permits them to hit moving targets if you update often enough. Not sure you could do that in something as small as a 155MM shell though.

If you have a laser guided shell, can you move the laser to follow a moving target? I would assume so.

You'd be surprised. Course-corrected shells are another hot development area, and incorporating both a GPS unit for fixed-target engagement, as well as a millimetric/IR seeker or laser for moving targets, is not really all that complex: the current crop of electronics allows seekerhead technology to shrink to the size of the fuzes alone we were using 20-30 years ago. And control sections (wings and fins) don't take a serious bite out of explosive filler. Of course, one benefit of the PGM is, you don't need as much explosive if you can hit your target dead-on every time. We are wowed at the capabilities that the defense sector reveals to us everyday. Question is: how capable is the stuff that they aren't telling us about yet?

>>Question is: how capable is the stuff that they aren't telling us about yet? We always seem to have something up our sleeves. Wonder what the skunkworks has? The thing I'm questioning is if we could feed a contiunuous update of the targets GPS coordinates to a shell in flight. I know it works for guiided bombs. A good combo might be GPS into 100 yds and IR the rest of the way in. Would make a deadly AMRAAM. GPS from BVR, IR WVR. Totally passive all the way.

All this assumes that GPS can produce sufficient accuracy. There are several error budgets to be considered: The CEP for a GPS location. The CEP for the ability of the shell flight control system to match the target coords with its GPS location at the moment of impact. The location of the target, since we must assume that a helpful person isn't going to stand on target centre with their DGPS this has to be fixed remotely. This means the location of a measiring device has to be accurately fixed, aand this deveice then measures polar coords (distance, verticle angel, bearing). These all have PEs and the resultant dimesions for angles increases with distnace. Putting all this together is proably only a few metres, however, while a few metres may not matter for a 250kg bomb with quite a lot of HE is does matter for a 155mm 45kg shell with 10kg of HE. Interestingly up to about 10km gun tgt range range it may as good to use dumb HE, say 3-5 rds! Modern dumb 155mm ammo is giving a PE of about 0.01% of range (and a lot less for line). The Brits used this sort of bunker busting in Basra.