Using a gps for marking property lines?
sominabtch asked:
I want to buy gps but need to know if I can do the following – will a handheld unit allow me to mark property corners (A – B for ex.), then plot a straight line from A about 3/4 mile through the woods to B? If so would the unit alert me if I am off (or on) that imaginary line? I want to do this for a fairly accurate idea of my property line(s).
The Next Generation in Handheld GPS Navigation
I want to buy gps but need to know if I can do the following – will a handheld unit allow me to mark property corners (A – B for ex.), then plot a straight line from A about 3/4 mile through the woods to B? If so would the unit alert me if I am off (or on) that imaginary line? I want to do this for a fairly accurate idea of my property line(s).
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Unfortunately, the civilian GPS systems available have a built in level of inaccuracy to avoid them being used for military purposes. You cannot depend on any of them for this kind of accuracy. You might be off 3′ or 30′. The big problem is, you’ll never know exactly how far off you are, and in what direction.
I would be happy with data from any handheld GPS for the purposed of hunting on my property. If I were 30′ on to someone else’s land, they likely wouldn’t know it unless they’d had it surveyed, in which case you wouldn’t be asking this question, of course.
I would not, however, feel comfortable using GPS data to set up a fence.
DeLorme GPS Units
In theory a lot of the hiking type GPS systems out there will do this.
The question is whether they will it well enough which depends on the accuracy you want.
A normal consumer GPS is only accurate to between 2 and 5 meters (6 and 15 feet) under ideal conditions. In a wood the accuracy will drop a lot more, trees block the signal a bit, a weaker signal means more error. Errors of 10-15 meters (30-45 feet) or more are possible.
If you can live with that sort of error then you should be fine.
If you need more accuracy then professional level civilian hand held GPS systems can give positions with errors under 30cm (1 foot) but with two big drawbacks for you. 1) the cost would be several thousand dollars and 2) they are designed for accuracy, if they can’t give an accurate position they won’t give any position. Which is great if you need to be able to trust the location it is telling you but lousy if you are in a dense wood where it’s not possible to get an accurate position.
The second limitation is normally overcome by using an antenna on a long pole and raising it up above the trees. But that isn’t very practical if you want to be able to use the GPS while moving.
So the short answer is that yes, it is doable.
It is fairly easy if you can live with errors in the 30-45 feet range.
It starts getting complicated and expensive if you want to do it accurately.