Blog · September 28, 2026
Accuracy of a Handheld GPS Next to an Iron Pin
Stand on a known pin and look at the error.
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Why this comes up
Stand on a known pin and look at the error. The miss distance you see there is the miss distance you should expect everywhere else.
What to check on the map first
County GIS lines are assessment maps. They are not a survey, and a product will not redraw them.
Open Platbookmapper and choose the state. The directory sends you to the county viewer. Match the parcel ID before you trust a pin on an aerial photo.
A tool that matches the job
Shop the Garmin GPSMAP when that is the job in front of you. The miss distance you see there is the miss distance you should expect everywhere else.
The limit
A handheld GPS gets you back to the truck. It is often several meters off, so it cannot tell you where the legal line is.
If the line is the real question, call a surveyor. The gear will not answer it.
Not a survey. County GIS and tax parcel maps are assessment and planning layers. They are not a substitute for a recorded plat, deed, or licensed survey.