[bane]

Ruger:

Perhaps the problem is with MIL-spec portable units, then. Because the ones we had mounted on the ship were considered the gold standard. It might have been because the Navigators were just lazy, I don't know. But I worked with them a good amount and never heard of GPS being inaccurate -- it always seemed dead-on. Then again, I guess at sea in the open-oceans a 10' variance isn't necessarily a big deal.

I understand what you are saying about speedometers.
I'm just saying that when I experience GPS being "off" by 10-30', frequently, I don't feel it's reliable as an accuracy instrument.

Which would I trust of the two??? I wonder if the answer lies somewhere in the middle... perhaps the GPS is hitting the "high" mean and the speedometer is hitting the "low" mean???

 

[Ruger Collector]

The GI units don't have a problem with accuracy, they're cumbersome and they devour batteries.

The civilian models are 'accurate enough'... When you're moving at a rate of 5280 feet per minute and you're measurement device is only off by 10-12 feet as to your exact location.

And as I said, the results were verified with other measurement devices and methods, which confirmed the GPS accuracy. So when visiting Duchesne County I'll keep an eye on my GPS speed reading.

 

[xmirage2kx]

The GI units don't have a problem with accuracy, they're cumbersome and they devour batteries.

Everything today devours batteries.

 

[Tarzan1888]

Up until a couple of years ago there was an induced wobble in all civilian GPS units.

That has been removed and you can get models that are accurate to within inches.

I use one in my work all the time and with its WAAS capability it is accurate to within feet.

With a GPS you get what you pay for.

Tarzan

 

[xmirage2kx]

With a GPS you get what you pay for.
Tarzan

I have a friend that bought a $80 GPS unit. After a year or 2 he decided to upgrade to a $400 unit. Same basic features, but the new one is usually within 10ft and the old one was 50ft. The new one will also map and plot courses etc, etc, etc while the old one just displayed a number.

 

[bane]

Well I did a bit of plugging around on the net regarding the GPS/Speedometer issue (since everyone seemed to agree, except me, that GPS's are more accurate at tracking speed... and since I couldn't see how that's true given me experience of them being sometimes widely off with distance... also the whole going up and down a hill thing seemed problematic to me). It turns out, you guys are right -- big surprise given the number of smart people who agreed!

I found this threadover at Groundspeak's forums (*THE* GPS people, IMO). None of the posts go into any detail to explain or resolve my questions but several people took the time to do a quick empirical check and found that GPS is pretty accurate (one guy said +/- 1MPH). There were several ways mentioned to do this: Ask a cop to help out using his radar gun, go find one of those "You are driving this fast" roadside boxes, or get on the freeway and time yourself between mile markers.

Personally, I was surprised, but there it is!