GPS Speed Accuracy

AvishP · Posted: Sun Sep 14, 2003 8:04 am Post subject: GPS Speed Accuracy

Hi all.

I`m a new member and after some great advice from the articles and members of these forums I finally took the plunge and bought a Haicom 303 (thanks DaveW!) to use InCar with My Axim PPC. Running TomTom it works very nicely indeed - a dream to use.

The only thing I did notice (and it's more for curiousity really) was that the GPS speed reading was actually quite far off the car speedo. The GPS showed around 62mph when the car speedo said 70. Now I know that speedometers are said to be up to 10% (up to 20%?) off anyway - but this still seemed alot.

If the Haicom blurb is to be believed, the velocity is accurate to 0.1m/s.

The question is - which is the one to be trusted...at the moment I`m inclined to believe the GPS...

Just think - all that time wasted when I thought I was doing 70 it was only 62...

Now I know why I`ve never been flashed by a Gatso...

AvishP

DavidW · Posted: Sun Sep 14, 2003 8:04 am Post subject: GPS Speed Accuracy

We discussed speed accuracy a little while back - take a look at this thread to see what we said. Essentially, the GPS is much more trustworthy than a car speedometer, which may underread by as much as 10%.

Glad you like the HI-303MMF / TomTom (presumably Navigator 2) combination - it's certainly working well for me and it all fits together very neatly in car.

David

AvishP · Posted: Sun Sep 14, 2003 8:04 am Post subject: GPS Speed Accuracy

Oops - apologies all for posting a new thread. I did search but somehow managed to miss the above (even tho' it was barn-door obvious). Apologies again.

@DaveW - It is a lovely combination...although at the moment the Car Mount consists of a willing relative holding the PPC up on the dash! Still hopefully it will arrive soon and all will be lovely... Thanks again for your help - I`m very happy and sure I`ve gone with the right solution.

AvishP

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