PawPaw wrote:I was reading an article somewhere yesterday that Iran is testing ballistic missiles that use GPS technology for targeting. The article stated that the best way to degrade the missile's accuracy was simply to turn off the GPS signal that reaches Iran when the missiles launch.
Perhaps the Navy wants to be sure that it knows where its ships are if the national command decides to turn off the satellites while the missiles are in flight.
Except that plan would probably have the same effect on the airliners of 110 nations (including our own) as would turning all the traffic signals in the country to green simultaneously.
We would likelier take the nuclear hit(s), and then just obliterate Iran with a second strike that would enlarge the Persian Gulf to the point of making Afghanistan a naval power.
We have "degraded" GPS signals in wartime.
Which, for nukes going for minute of metropolis, is nigh on worthless.
Turning it off entirely would be like setting yourself on fire to keep the enemy from getting your underpants.
There are lots of games we can play with our own (and probably European) GPS signals including degrading it and scrambling it, etc.
The best reason not to rely on it is that it actually isn't all that hard to jam.
Termite wrote: I suspect most ballistic missiles use internal gyros and programming for inertial navigation, so once the missile is launched, it probably doesn't need a GPS signal.
I'd be surprised if they didn't have it.
Even my cheap car gps can estimate location if it looses the gps signal. If I go into a long tunnel, it will simply assume I'm still on the road and at the same speed I was when I entered the tunnel, and keep tracking ahead as I drive. Then it will update the location once I'm out of the tunnel and it can get a fresh signal update. Last time i drove through a tunnel it was dead on when I got out of it and it got a signal again.
A missile would be easier since it has a fixed direction and presumably a fixed speed with no need to adjust speed for other vehicles. Once it's headed in the right direction and has a ETA, it wouldn't need the GPS for much more than verifying and maybe making small accuracy adjustments.
"Life is tough, but it's tougher if you're stupid."
John Wayne
We don't have to just "degrade" it. We could also tell it that it's hundreds of miles off course. Or, perhaps, at T+10 sec, that it has arrived, and should begin its terminal descent.
Brilliant Pebbles, before the left killed it, was a means to attack ballistic missiles during their launch phase before the war heads separated from the carrier. IIRC the "pebble" would detect a launch, the fire a braking motor, leave orbit, then home in for a kinetic kill.
Dinochrome One wrote:I see that my post got a severe haircut and a comment that I didn't write,......
Dinochrome, a thousand apologies!! It seems I wanted to quote your post and ended up editing it instead - I'm obviously not used to my amazing moderator powers yet. I'm very sorry, but I don't think I know a way to restore what I lost of your post...
Sorry
Ah, no harm & no foul. I was just saying that our lady-XO had to school the QMs on the Quapaw about celestial navigation back in 1984. Also, that she knew it well enough to keep us on course all the way to Hawaii with no electronic aids except our fishing-boat radar.
Maxim 34: If you're only leaving scorch-marks, you need a bigger gun.
Dinochrome One wrote:
Also, that she knew it well enough to keep us on course all the way to Hawaii with no electronic aids except our fishing-boat radar.
I don't know why, but that really kicked over my giggle-box!!!!
Thanks!
But there ain't many troubles that a man caint fix, with seven hundred dollars and a thirty ought six." Lindy Cooper Wisdom
