Using GPS to locate property lines

[Rob Tucker]

I have seen some inexpensive GPS equipment ($100?) for sale and want to know if I took readings at the property pins could I then find any point along the property line? I don't need accuracy to a centimeter. Within a few feet would be fine.

I know where the property corners are but the woods are too dense to make a line of sight observation. There are some old cane roads crossing the property and I want to figure out where the property line crosses these roads.

I guess I am basically wondering if the retail GPS gear is actually useful or basically junk.

Thanks in advance.



Chairman, Punaweb Committee, MSPA

[G. Leis]

They should work fairly well for your purposes - as long as frag grenade accuracy is all you need .

mella and I have a Garmin eTrex Vista handheld GPS unit with 3 meter (10' +-) accuracy which seems pretty typical for units of this size.

aloha,
Gene

[HADave]

Hi Rob, The Garmin models that Gene speaks of are available through LLBean and their starting unit Etrex sells for 99.00 ships to Hawaii 96720 for 7.95 receives in 6-8 days. best of all Beans warranty policy states if you are ever unhappy with a product no matter how long you own it return it for a no questions asked refund.

There website is http://www.llbean.com search for gps and see the full line of Garmin units. Hope this helps some also,

HADave

[Rob Tucker]

Great. So if I have point A and point B established these units can locate any point on an AB line. Is that correct?

The product descriptions I read do not make that clear and I have never used one.

Chairman, Punaweb Committee, MSPA

[G. Leis]

What the GPS unit will give you are the longitude/latitude coordinates of IT'S location at the time you take a reading.

AFAIK, it can't so much locate a point on an AB line as tell you where you are (coordinate-wise) once it is physically at that point. Perhaps a geocaching enthusiast or other expert can correct me if I'm wrong . . . always a STRONG possibility

aloha,
Gene

[HADave]

Perhaps this will help, an etrex owners manual... http://www.garmin.com/manuals/eTrex_OwnersManual.pdf

Just one tip when beginning a walk let unit stay at the starting point, still for at least 5 min to acquire as many satellite signals as possible, better for accuracy.

Heavy cloud cover or thick forest canopy can be a problem with maintaining Sat Signal lock with some models, they say external antennas help.

HADave



Edited by - HADave on 04/04/2006 15:57:23

[David D]

Hi Rob,
We had a similar situation last year. This is what we did:
We knew the location of the survey markers for each corner. There was no clear line-of-sight along the long sides of the property, which is 701’. Also, from looking at the TKM map of our area, we could see that the property lines ran parallel to our neighbors. And some of those neighbors had cleared & fenced their property. We wanted to stake the property line & didn’t want to pay for someone to do the work. Plus if you do this yourself, you really get an intimate feel with the land.
We bought a compass that is designed to take a reading (shoot an azimuth). We bought one at Wal-Mart for less than $10.00. We also bought some metal stakes, a roll of string, a mallet, and a roll of marking tape.
We took a compass reading along the fence line of two different parallel fences to make sure the readings were the same (they were) and then went to the survey marker on our property, started to make a trail along the same compass reading. We drove a stake at the survey marker & ran the string up the trail, set the string along the compass reading, then set the second stake. (We were able to go 100’ for the first stake after the survey marker. Some of the following stakes were shorter that 100’, but we never went beyond 100’ to set the next one)
By the time we made it to the other end, we were off line from the opposite survey marker by less than two feet. For clearing the land, that is an acceptable tolerance. Once the land is cleared, putting up a fence along the proper property line won’t be a problem.
For the compass, stakes, string, mallet, and marking tape we spent less than $50.00.
Now this is just MY opinion, but I don’t think those GPS readers are accurate enough in dense foliage to track a property line. +/-10 feet is a long distance. If you are just walking around & want to know your general location, GPS is great. It’s all a matter of determining the level of acceptable accuracy.

Good Luck!
David D




Edited by - David D on 04/04/2006 17:23:53

[Rob Tucker]

Thanks David,
I appreciate the input. I considered doing a compass path. The reason I hope GPS might be more practical is that the property lines run approx. 2,500', are not parallel and there are sections of nearly impenetrable guava.

I don't want to buy a gadget that doesn't do the job so I might just end up hiring a pro to locate the interior points.

Chairman, Punaweb Committee, MSPA

[David M]

Hey Rob

Here is a discussion of how someone did what I think you want. There's so extraneous stuff too, but how to do with GPS is pretty informative:
http://www.tractorbynet.com/forums/showf...vc/1/o/all

David

Ninole Resident

[Rob Tucker]

And thanks to you too David, that was an interesting read and right on topic. I do love learning from other people's mistakes.

Aloha,

Chairman, Punaweb Committee, MSPA