Actually it works amazingly well, though I can't tell you why. I had my
doubts as well, but the system appears to be accurate within a foot or so.
I didn't do anything scientific to test this, just looked at the difference
between laps when I know I was within a few inches of the apex cone and one
where I was about a foot away. I could clearly see the difference. I also
made a quick track map by driving two laps each on the outside and inside
edge of PIR. The map appears extremely accurate and locates the successive
racing line maps very accurately.
Probably has something to do with the fact that you need at least three
satellites acquired for the system to work.
-----Original Message-----
From: owner-fot@autox.team.net [mailto:owner-fot@autox.team.net] On Behalf
Of Chris Kantarjiev
Sent: Thursday, July 27, 2006 8:22 AM
To: fot@autox.team.net
Subject: Re: [FOT] Data acquisition
> A little more about this--you can map a track by driving around the
> inside and outside edges. the GPS locates you with great accuracy.
I'll be very interested to know how this works out in reality. Autonomous
GPS accuracy is about 15' - you can't do a lot better than that with a
single receiver. That's almost the width of the racing surface!
(Google for "GPS precession" if you want to know a whole lot more about
this...)
With differential GPS, you can achieve much greater accuracy, but you need a
fixed data reference. The DoD is putting up extra satellites to implement
something called WAAS, which will also improve the accuracy ... but still.
It's never going to be better than a few feet.
Best,
chris
|