Military History | How To Make War | Wars Around the World Rules of Use How to Behave on an Internet Forum
Artillery Discussion Board
   Return to Topic Page
Subject: Excalibur GPS
Smoke WP    3/11/2007 4:32:48 PM
Question for our resident experts. Is it possible to interupt the GPS signal being sent to a guided projectile?
Quote    Reply

Show Only Poster Name and Title     Newest to Oldest
B.Smitty       3/11/2007 4:41:32 PM
Of course. Signals can be jammed.  Satellites can be destroyed.

Quote    Reply

Smoke WP       3/11/2007 5:04:38 PM
If we ignore the obvious( destroy all 24 satellites) which is near impossible to do.
Is there a battlefield device that would jam signals to GPS guided projectiles?
Being that Excalibur projectiles are scheduled for battlefield deployment in Iraq and Afghanistan, just wondring how good these projectiles are.
Quote    Reply

HIPAR       3/11/2007 7:48:52 PM
There's a briefcase sized GPS jammer that's openly sold.  I don't know how effective it is.

There is a mandate for defense systems to use the encrypted GPS channel that is inherently more difficult to jam because of its spread spectrum signal structure.  Also, GPS is to be used in conjunction with a second guidance system to mitigate the effects of jamming..  An inertial system that receives updates from GPS is common.  When jamming is detected, inertial guidance does its best to complete the mission.

I would hope Excaliber is designed with jamming having been considered.

---  CHAS

Quote    Reply

Jeff_F_F       3/12/2007 1:36:59 PM
I doubt we'll soon be that dependent on Excaliber that it would be a catastrophe if we couldn't use it. Our FA is pretty good about practicing degraded ops. At least my NG unit was. We still practiced with charts and slide rules, and even had to use them for real a few times when the LCU computer went down. And unless guidance is added to all rounds we'll *have* to practice at least computer aided fire direction. For example, I can't see creating a GPS-controlled smoke round, it would make a smoke mission a lot easier but would be overkill. Using GPS guidance for DPICM seems kinda like using a sniper scope on a shotgun. High tech hardware is great but you have to practice degraded too or Murphy will kick your butt.
Quote    Reply

Carl S       3/12/2007 6:44:11 PM
"At least my NG unit was. We still practiced with charts and slide rules, and even had to use them for real a few times when the LCU computer went down."

Oh gosh, the nostalgia brings a tear to my eye.   (sniff)

I corresponded with a a major who was a inf bn ops officer during OIF.  He was able to recall the response times for the various artillery missions they monitored,  As I expected  the response times from intitial call for fire to FFE was not noticablly faster than the graded times for the old charts & darts era.  He identified one unit as being hopelessly slow (nearly ten minutes).  
Quote    Reply