handheld gps advice

[99guy]

Anybody know a good site for info on handheld gps units?



I have a need for one to lay out some parallel lines on our farm. I have Delorme with the older gps unit on a laptop but the accuracy seems to be no better that 30 feet or so at times. Maybe this is the best any of them will do??? Don’t want to spend a lot either as I don’t really need any other bells and whistles. Any advise appreciated.

 

[JR2]

I think that is about as good are you are going to do. My Garmin Etrex will occasionaly tell me the accuracy is down to about 10 ft, but not very often. It all has to do with how many satellites the unit is locked onto and the quality of the signal.



You used to be able to get what they called a differential reciver that was used to pick up a seperate land based signal from the US coast guard that would tell your GPS what the differential error being used was, but that is a moot point now that the defense department turnd off the error inducing software for location (the error for altitude is still turned on).

 

[MGordon]

30' is about as good as it gets for an older unit. The newer units can achieve around 20' accuracy 95% of the time.

 

[klenger]

If you can find a GPS that is WAAS enabled, you should be able to get better than 30' accuracy, but still not surveying accruacy.

 

[slo-ryde]

Garmin claims 3 meter accuracy 95% of the time with WAAS enabled units. That's around 10 feet, probably the best you're going to get.



To answer your question: www.garmin.com has great info on how GPS works.