U.S. May Reduce Non-Military GPS Accuracy

ward99 writes "The U.S. government may be degrading GPS satellite signals, to cripple Iraqi forces' ability to use those systems during the war. This could potentially reduce accuracy from ~3 meters to over ~100 meters. Users depending on GPS systems may want to do sanity checks on any data returned by those systems during the war. The U.S. will do this by increasing the inaccuracies on the civilian C/A code, turning back on S/A (Selective Availability), by having the satellites deliberately and randomly return inaccurate information on where they are. S/A degrades GPS accuracy to only 100 meters 95 percent of the time and 300 meters the other 5 percent of the time. This will not effect the military P code."

Comments

Re:Sanity checks..

[zCyl]

Which sane person would rely on GPS data for something even as trivial as navigation?

Have you tried navigating by the stars during the day lately? The blue room can be a big scary place.

In other news today...

[Noryungi]

John R. Smith, of Peoria (Ill.) drove his brand-new SUV through the security glass doors of his bank, while following his GPS navigator.

"I was only following the indications of this @!!%!! machine -- and it told me I still needed to travel straight ahead for a hundred meters!", Smith tried to explain as he was taken into custody by the Peoria Police Department for "breaking and entering".

The Peoria Intercontinental Bank representatives were unavailable for comments.

onstar?

[Joe the Lesser]

Don't a number of commercial services like onstar use gps to track vehicles?

'Be calm madam, you are not lost. According to us you are floating off the coast of San Diego. You should be fine once high tide rolls in.'

Re:onstar?

[Lxy]

I've got a friend in MN. One winter night he and his buddies decided to have some fun with Onstar. Knowing that the call center is somewhere in Florida or California, they drove onto Mille Lacs lake (a very huge lake for those of you who don't know, it's larger than most counties). They called up Onstar to ask for directions:

Onstar: "hello?"

Friend: "We're lost. Can you help us find our way back?"

O: "Sure, hold on. Hmm.. this must not be working right. It says you're in the middle of a lake!"

F: "I know. We need to find our way back to shore"

O: "????"

F: "We're in Minnesota. There's ice on our lakes here"

O: "???? How are you in the middle of a lake?"

F: "We drove out on the ice"

O: "Why would you do that?"

F: "Ice fishing"

O: "?????"

F: "Can you direct us to the nearest landing?"

O: "Umm.. hang on a second. I need to get my supervisor."

Re:So the US sold the GPS equipment as well?

[mgblst]

A joke in The Australian newspaper the other day:

Reporter: So how do you know that the Iraqis have Weapons of Mass Destruction.

American: We kept the reciepts!

boom boom.

Re:this is reliable info

[realnowhereman]

Of course - I forgot that the American chiefs of staff have a strict policy of inform and consult with the German auto club.