D
Dave Liquorice
Guest
On Fri, 10 Jun 2005 18:53:26 +0100, Peter wrote:
> GPS is already two way as we use it on marine position finders to
> add pinpoint accuracy. It's called SdGPS (Satellite Differential
> GPS).
AIUI, differential GPS is not two way in that there is an out going
link from the receiver to elsewhere. What it does is utilises another,
terrestial based, signal from a transmitter whose location is known
very accurately. A differential GPS Rx then uses that signal with the
ordinary GPS one to correct the inherent GPS errors.
> If it's not receiving a signal the car won't start!
So what do you do if you park under trees or in a garage?
--
Cheers [email protected]
Dave. pam is missing e-mail
> GPS is already two way as we use it on marine position finders to
> add pinpoint accuracy. It's called SdGPS (Satellite Differential
> GPS).
AIUI, differential GPS is not two way in that there is an out going
link from the receiver to elsewhere. What it does is utilises another,
terrestial based, signal from a transmitter whose location is known
very accurately. A differential GPS Rx then uses that signal with the
ordinary GPS one to correct the inherent GPS errors.
> If it's not receiving a signal the car won't start!
So what do you do if you park under trees or in a garage?
--
Cheers [email protected]
Dave. pam is missing e-mail
