How far will my GPS be off?

[bobc455]

So now that the earthquake in Chile has changed the earth's rotation, when will they fix our GPS's? They depend on the earth's position for location, and since the rotation is now off by 1.26 milliseconds per day, those things will go haywire pretty quickly. I've already noticed mine has had a hard time putting me on the right road, and it's been less than a week.

Anyone have the inside track?

-BC

[shatto]

I'd blame that on the altimeter being off below 100' but that was before the quake.

[FrugalFloyd]

Not to worry. The Earth was only slowed 1.26 microseconds. I'd hate to think how bad things would be if we'd lost 1.26 milliseconds.

[bobc455]

Well right, but the 24 satellites which were previously geostationary are now moving a bit in relation to the earth's surface.

I did learn that as of yesterday, the earth's position was only off by 3". So I guess we have a while before it is off by more than a few feet, but only a couple of months or so.

-BC

[Jay2TheRescue]

I remember when daylight savings time changed a few years ago (Remember when they actually changed the day it happens?) My GPS at the time hadn't received that update yet. I was driving somewhere that day, and my GPS was tracking me about 100 yards west of my actual location. I got real tired of hearing my GPS say "In 100 yards turn right, then turn left" every time I approached a cross street. It continued to do that until it dawned on me that the clock was wrong, and I manually reset the clock.

[bobc455]

If your GPS was off by 100 yards, you have to remember that is equivalent to how many seconds it takes light to travel 100 yards.

In other words, that wasn't your issue...

-BC

[Jay2TheRescue]

I'm not sure. As soon as I reset the clock the unit was accurate again.