can a GPS be used to be to tell accurate speed?

[juanblzer]

I don't have a speedo but I should probably have one for my upcoming interstate trip. I want to buy a GPS but I am wondering if the speed it says you are traveling at: is actually somewhat accurate.
juan

 

[HarryH3]

It's only accurate to about one TENTH of a MPH. /forums/images/graemlins/eek.gif /forums/images/graemlins/wink.gif I use mine to check the accuracy of my speedos. /forums/images/graemlins/thumb.gif

 

[gjk5]

I have never seen a difference in my speedo and the reading on my GPS, so yes.

Don't know if you've ever owned a GPS, but do some research, prices and functions vary greatly.

 

[jarheadk5]

As long as the GPS unit is receiving a good saellite signal , it'll give you about the most accurate speed indication you can get.

 

[HarryH3]

I don't know how the signal strength is back east, but here in Colorado I've never seen fewer than 6 satellites available at one time on my Magellan GPS 315, even when mounted up on the dash. /forums/images/graemlins/thumb.gif It often shows 6 or 7 with plenty of signal available. /forums/images/graemlins/cool.gif

 

[jayweb]

why not get one of those new gps speedos from nordskog (like they use on offshore powerboats)?

 

[jarheadk5]

Depends where I'm at. I can usually get 4 sats in my driveway, and never less than 5 sats in the park. Driving around the backroads in Jersey though is another story. Some of these roads have triple-canopy-jungle-type overhangs, and the signal just can't punch through...

When I was on the summit at Pila in the Italian Alps (8600ft), I had 10 sats with full signal bars - accuracy was 3 feet!