Excalibur 155mm GPS guided shell--in or out?

[John Kettler]

I saw test firings with this nasty bit o' kit the other night on Future Weapons, and I must say it's going to radically change what we expect from the Redleg community. It's not just the phenomenal (if giving), nightmarish (if receiving) accuracy (saw 2 meters demonstrated), but the ability to do things which were either impossible before or pretty dangerous.

One new capability which should really change the nature of MOUT is that FA is no longer dependent on pure ballistic trajectories to determine what it can and can't hit. It is now possible to engage and hit targets such as mortars on the back sides of buildings because the GPS kit steers the projectile in ways a pure ballistic path never could.

Another one which really got my attention was a deliberately misaimed at the gun shoot (15 degrees off axis), creating a 4 mile offset at GPS guidance activation. This was a program make or break, and Col. Tanzi, who heads all of FA development, was there in person. Someone bet the shell wouldn't land within 5 meters (sorry for the mixed units, but that was how the show was done), and now owes the colonel a fabulous lunch. This was the shot I mentioned earlier which landed within 2 meters of the aimpoint. The ability to offset aim makes it much safer to work artillery in close proximity to friendlies, since the approach path can now be adjusted so they're not under it.

All in all, I was very impressed with what I saw.

Regards,

John Kettler

[SgtMuhammed]

The ability to offset aim could also reduce the effectiveness of counter-battery fire. CB solutions simply figure a ballistic course.

Is the old Copperhead still around? My CO's track was killed by one "simulated" in '99 but I haven't heard to much about them lately.

[Peter Cairns]

The AMOS mortar system has a neat ability to alter the trajectory and speed of rounds so that the first half dozen or so all land similtainously.

That can give people a nasty surpriese and is also usefull for hitting concentrations in shoot and scoot. I think it can also fire direct.

Peter.

[Jaska.]

How can an artillery projectile be guided inflight ?

Did I understand correctly that the shell will alter its flying trajectory while flying towards the target ?

How is this possible ?

[John Kettler]

sgtgoody (esq),

I hadn't thought about that before, but I think that much would depend on counterbattery radar LOS. I strongly suspect that unless, say, the shot is fired out of a deep valley, such that GPS guidance has begun before the shell breaks radar mask, I doubt it would do much. Certainly, in relatively flat ground, where counterbattery radar, if it survived long enough to be useful, would detect the shell almost as soon as it was fired, would get two or more successive position cuts within seconds thereafter, and the firing location would be backplotted and counterfire could be on the way before the inbound shot even landed.

I think the Copperhead's still around, but that's not the same as knowing. Via Russia, the Syrians can be supplied with a whole family of Copperheadskiy artillery shells and rockets: 122, 152, and Grad, among others. Believe there's also a 120mm mortar round.

Peter Cairns,

What you describe seems to be an emerging trend for modern fire support systems. What was done

in World War II using separated batteries and battalions conducting TOT shoots, now rejoices in the acronym MRSI (multiple rounds, simultaneous impact) and takes only one tube.

Prinz Eugen_2,

The shell has a GPS receiver which continuously "tells" it where it is, information which is constantly compared to where it was "told" to go.

This 3-D (maybe more, since velocity and time may also be factored in) information is then applied as steering commands to a set of pop-out guidance fins. These fins allow the shell to escape from the worst of the prison imposed by the laws of ballistics, in that the shell can now do things a simple ballistic body could not, though the original energy budget remains the same.

Regards,

John Kettler