Property lines

[ultrarunner]

The county had a GPS "Survey" done along one side of my land. The Surveyor was very friendly and showed me how it worked.

He said accuracy is a function of the number of satellites and known reference points. He had 3 small transmitter/receiver antennas set up on 3 surrounding hilltops. He told me the accuracy of the stakes he was setting was within 8 inches and using GPS technology allowed a single man to do thee work that previously required several men.

 

[SnowRidge]

The county had a GPS "Survey" done along one side of my land. The Surveyor was very friendly and showed me how it worked.

He said accuracy is a function of the number of satellites and known reference points. He had 3 small transmitter/receiver antennas set up on 3 surrounding hilltops. He told me the accuracy of the stakes he was setting was within 8 inches and using GPS technology allowed a single man to do thee work that previously required several men.

Yes, but go price GPS based surveying equipment. It is very expensive, and you can't do it with consumer grade GPS equipment. You are talking an entirely different ball game.

Eight inch accuracy seems pretty lousy to me for a professional surveryor.

 

[ultrarunner]

The county order a tree survey of all Oak Trees with a 4 inch or greater dia. at breast height and all other trees 8 inch dia. or greater at breast height.

Guess there is some wiggle room depending on whose breasts are being referenced? Sorry, it just sounded funny when he explained it...

 

[shaley]

Consumer grade GPS reads to a 3 place decimal. 6070 ft in a mile so the resolution is +-6 ft. That is resolution only and accuracy can't be better than than stated resolution and most are about +- 15 feet with the WAAS system functioning.
Surveying GPS is much different. Sometimes it takes 20 minutes to acquire a position with full post processing but it will be +- 1 CM (3/8"). These units sell for about 15k so it saves the surveyor time by not requiring a clear line but cost him money which he passes to the customer
The real time in marking property lines is clearing the brush for line of sight. Clear your line and ask a surveyor what he would charge to shoot the line. I bet he could do it in an afternoon.

 

[SnowRidge]

Consumer grade GPS reads to a 3 place decimal. 6070 ft in a mile so the resolution is +-6 ft. That is resolution only and accuracy can't be better than than stated resolution and most are about +- 15 feet with the WAAS system functioning.
Surveying GPS is much different. Sometimes it takes 20 minutes to acquire a position with full post processing but it will be +- 1 CM (3/8"). These units sell for about 15k so it saves the surveyor time by not requiring a clear line but cost him money which he passes to the customer
The real time in marking property lines is clearing the brush for line of sight. Clear your line and ask a surveyor what he would charge to shoot the line. I bet he could do it in an afternoon.

I just had a survey done. It was rather complicated in that it plats four separate parcels. I was on the property with them when they did it, and they will be doing another one for me on another piece of property Wednesday.

They did not have to clear any brush, except for two of the corners which were completely overgrown. To get from one corner to another that couldn't be seen, which were most of them, they ran traverses instead of clearing the brush, which in some cases were full grown trees. I asked for a mid line mark at one point. They couldn't see it from either corner, so they ran a traverse to locate it. It only took them a few minutes.

 

[MossRoad]

I just had a survey done. It was rather complicated in that it plats four separate parcels. I was on the property with them when they did it, and they will be doing another one for me on another piece of property Wednesday.

They did not have to clear any brush, except for two of the corners which were completely overgrown. To get from one corner to another that couldn't be seen, which were most of them, they ran traverses instead of clearing the brush, which in some cases were full grown trees. I asked for a mid line mark at one point. They couldn't see it from either corner, so they ran a traverse to locate it. It only took them a few minutes.

Pretty soon we'll be talking about surveying saying something like, "Back when it was a skill and not a task."

 

[Willis Fecon Bushhogging]

I used a GPS to set my boundaries. I started by landmarking the front corner, then turned off the meter, went to the back corner turned it back on and landmarked it. The GPS automatically drew a straight line between the two landmarks. I then followed the line back, marking trees as I went.

I have a Fecon FTX90L mulching machine and I was thinking of doing the same thing with the GPS. Just wondered what model you used. I am a retired boat Captain and I really liked the Garmin brand.
Thanks for a reply

 

[SnowRidge]

Pretty soon we'll be talking about surveying saying something like, "Back when it was a skill and not a task."

It's still a skill. They used to run traverses in the "old days." They still do it with modern equipment. I couldn't begin to do what these guys did. The guy in charge was a CE and a Registered Professional Engineer. I'm sure his bill will reflect that.

 

[firedog]

I have a Fecon FTX90L mulching machine and I was thinking of doing the same thing with the GPS. Just wondered what model you used. I am a retired boat Captain and I really liked the Garmin brand.
Thanks for a reply

I used a magellan 315 handheld. I've had it several years, and am quite sure there are much better ones out now. My thinking was not to necessarily set the boundary or fenceline with it, but give me a good idea of where to clear the woods. My corners have been marked, and I've already turned the angles and fenced the front 1 1/2 acres, But the back is heavily wooded. No real way to move off to the side and shoot any measurement, as its all wooded.
(plus I'm on the cheap side) The land slopes at an angle about 45 deg off from the property line, which gives you a natural tendency to veer off from the direction you started it.
I'm clearing about a 15' - 20' swath, so I can come back and shoot it with a transit.

 

[RonMar]

We bought the same GPS and I'm trying to figure out how to load up the right files. It can't be less accurate than a hand held compass and the Mark I eyeball. Dan

Unless it is a GPS specifically designed for survey work, you can easilly beat it's accuracy with a plumb bob and carefull sighting along plummed stakes. The calculating function of a survey GPS is of a higher resolution, mostly due to the averaging of the input signals. Perhaps the biggest differance between one and a consumer grade handheld is the antenna used. Consumer handheld GPS's are a comprimise of function and size/form with the antenna being a small portion of the entire package. Survey GPS units are typically mounted on a handheld pole with the receiver on the side and the antenna affixed to the top. the antenna is easilly as large as the receiver. The larger antenna allows a higher signal to noise ratio which allows more sattelites to be tracked(and more average samples) at a given location, particularly when back under the trees. The extremely precise units have an antenna that is quite large(14"-18" across) and cost many times what the precision receiver does.