Posted on 04/29/2005 3:30:21 PM PDT by finnman69
Most definitely.
The satellite part doesn't surprise me, what does is that video of the scene was collected and recorded. This was at one checkpoint of hundreds, the fact that they dedicated one satellite (or one camera on a satellite) to a relatively unimportant location can only mean that they have tremendous coverage. Just think of all the better places to point one of these things . . .
I don't know much about how JSTARS operates, but I have been out on a patrol and the TOC came over the command net and told us to go check out so-and-so coordinates due to JSTARS reporting activity there. When we got there, there were a few farmers milling about (I guess they were suspicious because it was the middle of the night, but Iraqis often work their fields at night due to the heat of the day). Anyway, I don't think they were given that area as one that was especially important to scan, they just noticed movement, so it would seem to me that they would notice a car speeding towards one of our checkpoints and take notice thus providing the evidence here.
Interesting! And thank you for your service.I worked at Grumman, the orignal builder of J-STARS and now merged with Northrop. Worked on testing A-6 Intruder software, but never did anything on J-STARS, which wasn't done on Long Island but down in Florida. I just know that it's a heavily computerized radar sytem built into a Boeing airliner airframe, and that it'll tell you a lot about vehicular traffic.
Intended to provide detailed info on any Warsaw Pact invasion of Western Europe, but the USSR imploded about the time of Desert Storm - and the first two prototypes were pressed into service during Desert Storm. General Schwartzkopf (sp?) remarked afterward that J-STARS had been far too valuable for the Army to ever be willing to part with.
No complicated mathematics required. Just simple arithmetic:
The car traveled 91 yards (137 yards minus 46 yards) in three seconds. Assuming constant velocity, the velocity V is given by the following formula and conversion factors:
V = (91 yd / 3 sec) * (3 ft/yd) * (1 mi / 5280 ft) * (3600 sec/hr)
V = 62 mi/hr
LOL, as a fellow RIVET JOINT person, I whole heartedly concur. That being said, my first thought when I saw this article was COBRA BALL.
foxfield, you have the correct calculation but you do not have to assume that the velocity is constant. We have no way of knowing that. The result of your calculation is the average velocity of the car for the satellite observed segment. And for this argument this is all they needed, because 60mph is a long way from 30.
chopperman, the reason your calculation comes out wrong, is that you assume the final velocity is 0. We have no way of knowing that either. With the the data the satellite gave us we can only calculate the average speed as foxfield did...
Just for meanness let's assume that the vehicle, when disabled, slowed down with a friction coefficient of 0.8. Unless the troops were using artillery, they couldn't stop it instantaneously, it would just lose power and stop rolling efficiently on its wheels as the engine, tires, and driver's steering lost effectiveness. If in fact the car was going 60 mph (88 feet/sec), the time it would take to stop was approximately
88ft/sec/(0.8 * 32.2 ft/sec2=3.4 sec
distance = 1/2 at2 = 0.5*(.8)*32.2*3.4*3.4 = 149 feet, or 50 yards.Sounds like it might have taken longer for this to happen than CBS asserts - or the data could be more consistent with a slower initial speed.
If in fact the car was stopped in a distance of 50 yards, the car would have had to travel (137-46) = 91 yards before being disabled.And if its speed was 60 mph (88 fps), that allows a time of
91*3 feet / 88 ft/sec = 3 seconds from the time the car is spotted until it is disabled.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.