I'd quite like to add a few more markers within the trees, just so we know
where the boundary is (and maybe fence at a later date) - question is, how
to mark it out? The woodland's too dense to see through to the other side,
even at night with a flashlight on one of the markers, so I can't just
walk and "home in" on it.
I'm not sure that GPS is accurate enough to do it that way - any other
clever tricks?
Did wonder about running two lines, meeting at one of the markers. All I
need to do is get them straight through the trees (which might be a
challenge in itself) - then I can presumably measure distance from each
to the other marker at the far end, translate that to a scrap of paper,
and calculate where the "true line" is between the two markers for any
given distance along one of my guide lines. Does that make sense? Maybe
there's a simpler way, though...
Ideas on a postcard, or on usenet, whichever is easier.
cheers
Jules
> We've got a bunch of woodland that's partly on our property and partly on
> a neighboring (vacant) plot. Runs for about 300' or so, and there's a
> boundary marker either side of the woods.
>
> Did wonder about running two lines, meeting at one of the markers. All I
> need to do is get them straight through the trees (which might be a
> challenge in itself) - then I can presumably measure distance from each
> to the other marker at the far end, translate that to a scrap of paper,
> and calculate where the "true line" is between the two markers for any
> given distance along one of my guide lines. Does that make sense? Maybe
> there's a simpler way, though...
>
>
You did not say why. If you are just looking for a general idea of
how big the lot is, then running down the trees is okay. If you want to
actually do something like build a fence, etc., then you probably should
get it surveyed.
--
To find that place where the rats don't race
and the phones don't ring at all.
If once, you've slept on an island.
Scott Kirby "If once you've slept on an island"
Ahh, there's a possibility that the vacant lot is going to be sold, so I
figured I should maybe mark the line a bit better than just the two
boundary poles. The lot's shaped such that any buyer would be unlikely to
pull trees down to put a building in (it's about 4 acres I think and the
extra effort of taking down an acre of trees doesn't seem sensible) - but
some folk can be strange :-)
We might just buy it ourselves eventually, but have too many financial
commitments for the next 3 months to think about that (OTOH once the snow
hits I bet it won't get much interest until next Spring)
> If you want to
> actually do something like build a fence, etc., then you probably should
> get it surveyed.
Yes, calling in a professional is one option, although I'm curious how
they do it when they don't have line-of-sight either. I doubt 6" either
way is any big deal (it's just not the sort of place where people get
pissed about that kind of thing!) but I'm not sure if GPS is quite that
accurate (at least not the civilian stuff)
cheers
Jules
> On Thu, 19 Nov 2009 16:54:28 -0500, Kurt Ullman wrote:
> > You did not say why.
>
> Ahh, there's a possibility that the vacant lot is going to be sold, so I
> figured I should maybe mark the line a bit better than just the two
> boundary poles. The lot's shaped such that any buyer would be unlikely to
> pull trees down to put a building in (it's about 4 acres I think and the
> extra effort of taking down an acre of trees doesn't seem sensible) - but
> some folk can be strange :-)
Then it would have to be surveyed, at least according to the way
they do things around Indy.
Run a line parallel to the existing markers but outside the wooded
area. Then from any point you like on the reference line, measure
perpendicular into the woods the same length as the offset of the
outside line from the end markers.
No, a GPS is definitely not accurate enough for that purpose.
But all they would do would be to confirm the location of the existing
boundary corners--no need to survey where the straight line between two
marks actually runs for the legal description so they won't do so.
As for finding the line itself lacking line-of-sight, manually it's
painstakingly working one's way thru from one sighting to another.
I don't know what the inexpensive handheld GPS gizmos can do; I've never
had one or looked to see as never really cared that much. BUT, US WAAS
static accuracy is +/- (roughly) 30". This is what's freely available
but not guaranteed availability.
Additional corrections can be made to a single signal but afaik these
are all subscription services and whether the cheapie devices include
that cost in the upfront purchase cost I don't have a clue.
We use John Deere AutoTrac(tm) with their proprietary SF2 subscription
service on the tractors/spray rigs/etc. which has an absolute static
accuracy of +/- ~10" but repeatability of tracking of better than half
that (the latter is the more critical for our purposes of controlling
row spacings and spray coverage as opposed to your desire to know where
a point is physically located).
So, all in all, I don't know what you could get inexpensively but I'd
expect more like the 30" rather than the 10" numbers.
FSA (USDA Farm Service Agency) uses GPS to do monitoring/compliance on
acreages but they, of course, have access to whatever level of
technology the DOA(griculture) has access to. They routinely print out
computer-generated maps down to the 0.0001 mile (1/2") but I seriously
doubt the data are that accurate only that that's what their silly
compter output formats are. I'd guess they're roughly at the 10" value
overall although I don't think any of the technicians nor even our
office director have that level of knowledge of the technical
details--only how to use the supplied equipment and software systems.
I routinely measure fields by the rolling wheel technique for waypoints
in the total field for operations such as haying or similar and ignore
anything less than roughly 1/10A (which is a strip roughly 1/2-ft wide
over a half-mile row) and have never been called to task. That close is
reasonably easy to get as each revolution on a rod wheel is 1/4 of
16.5-ft or 4+ ft so 1-ft is a quarter revolution. 1-rod by 1/2-mile is
1A and most of our land is farmed in quarters which are 160A or 1/2-mi
square so that's far more convenient measure rather than feet-inches by
hand. The JD AutoTrac readouts can be switched to whatever units one
wants since it's all computer-based, of course.
But, all that to say the higher accuracy GPS numbers above don't come
cheaply (at least w/ green paint (or red, either, for that matter).
--
Aha - yes, that's a good plan. There are really too many buildings on our
side of the line to do that, but I can do it from the vacant plot (the
folk who own it currently are good enough that I know they won't mind)
cheers
Jules
I did a fairly good job finding my lines using an "engineers compass"
and a plot plan. The "engineers compass" is like a tiny cheap hand held
version of a transit, but worse, it came from WalMart. Very very basic.
Wait for all the leaves to fall. I went to the one and only corner
marker I could find and using the compass turned the plat map so North
is North. Aimed the compass site using the compass markings and lining
it up with the line on my map. Sighted through a tiny lens and a single
cross hair as far as the next tree it hit. Walked to that tree and did
it again. Kept doing that until I found the other corner markers, and
in 600 or so feet I was off by 6 feet. Sure that's a lot for some
things but I just wanted an idea of were the corner of my property was,
and there it was, well marked.
Turns out the other land owner had some pro's come through a couple
months later. He showed me one place I had marked, about half way
between corners, I was off by only 6 inches there and he acted like that
was a lot. Only reason I ended up 6 feet off in the end was due to the
terrain. A lot of it was literally stretching and climbing up the
mountain a couple feet at a time and getting myself on the uphill side
of the next tree to rest against. I accidentally rode down the mountain
on my ass with a shit load of leaves under me and in front of my feet.
It was kind of fun.
As far as markers, they use an ax and take off the topmost part of the
bark, it didn't get down to fresh wood. Then those spots were painted
blue. Some with 4 blue lines like a square, some just 1 or 2 marks.
I'm guessing the marks meant something that had to do with were the
exact property line was... in front or in back of the tree.
There was one spot where I am close to the property line and they marked
it with the 4 blue marks and a small yellow no trespassing sign in the
middle. It seemed to stick out like a sore thumb and from the driveway
it drew your attention. So I mixed up some mud, real mud, dirt and
water, and plastered over the blue marks. And I got a few large leaves
to stick on the nail holding the little sign. Now I don't see it, but
it's still easy to find if you are close and looking for it.
How tall is the tallest tree between the markers?
The products shown here range from 18 feet (Sale Price: $6,050) to 41
feet (Sale Price: $28,315).
http://www.artificialplantsandtrees.com/Trees/Big_Trees/big_trees.html
Buy 2 that are just higher than the tallest existing tree, tie a
string to the top of each one and stand them up right next to the
markers..
QED
-------------------------------------------------------
We were trained how to do something like that with a compass during basic
training many years ago.
Perhaps you can find a new soldier who has recently had that training to
help with your project.
Freckles
No, I don't have a high power laser listed on Ebay for such
a purpose.
I doubt this is workable, but it's fun to imagine.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"Jules" <jules.rich...@remove.this.gmail.com> wrote
in message
news:pan.2009.11.19....@remove.this.gmail.com...
We've got a bunch of woodland that's partly on our property
espically if you are planning on a fence
It's possible that you can locate the corners yourself by zooming in on
Google maps -- I just checked it out and can on my house -- even though
there are a lot of trees blocking the view I can still pick out enough
landmarks to be able to draw a property line.
The surveyor I talked to during the summer told me that his old model
was accurate to an inch, and his new model to a tenth of an inch.
I think these were 20 to 40,000 dollars, but still they meet the
definition of a GPS. :)
Since the lot next door isn't wooded, that's your solution.
I once worked for a survey company for a few days (a long time ago) and my
job was to cut "sight lines" through a wooded lot that was going to be
surveyed. It was no fun -- mostly just hacking away brush and small trees
to be able to see from one end of the lot to the other. It involved
multiple sight lines because the survey had to also show the elevation of
the land on the interior section. I guess there were no other magic tricks
the surveyor could do so he had to pay us to chop sight lines all day long
for a few days. We were doing it in the middle of a hot summer.
If you do end up having to chop any sight lines, it will be a lot easier if
you can wait until winter after all of the leaves have fallen off the trees.
I seriously doubt the OP was talking about the very expensive and
accurate type of GPS used for surveying. I'm not sure one would work
for his particular application anyway, as those units need open sky
above to achieve that accuracy. This is a thick grove of trees...
Good point. Not sure but maybe I just wanted to tell about how good
the expensive ones are.
That's what I did. A straight line from one marker to the other was
blocked by trees between the two, so I measured ten feet away from the
each marker into my property and stuck a temporary stake into the ground
at each point, then strung a line from one new stake to the other (300
feet away). I could then mark off divisions in the property line along
its length by measuring ten feet from the new line to the actual
property line.
--
Bill
In Hamptonburgh, NY
In the original Orange County. Est. 1683
To email, remove the double zeroes after @
Not only that but public grade GPSs can be off by a meter (3' 3")
As has been pointed out, surveyors have GPS devices that cost a lot of
money, and are accurate to 5 millimeters. We are not talking about
inexpensive consumer units that tell you to turn left when the road
curves right.
wonder if you can rent one of those super dooper GPS units?
Interesting - didn't know that, and I think I'd quite like to get a copy
anyway (whether it's useful or not), particularly if it's something that
might be a few years old (we're on the central lot of what was once a
farm, so have lots of farm buildings - but there were various ones that
were pulled down before we moved in, so it'd be interesting to see an
overhead view of the place before that happened)
I guess as the boundaries don't change they don't retake photos that
often.
> It's possible that you can locate the corners yourself by zooming in on
> Google maps -- I just checked it out and can on my house -- even though
> there are a lot of trees blocking the view I can still pick out enough
> landmarks to be able to draw a property line.
No joy there unfortunately - we're pretty much out in the wilds so it's an
area where they haven't done high-res data yet. I'm kind of hoping they
don't until after I re-roof the barn, then I can leave them a nice message
on the top ;)
cheers
Jules
> "Jules" <jules.rich...@remove.this.gmail.com> wrote in message
> news:pan.2009.11.19....@remove.this.gmail.com...
>> On Thu, 19 Nov 2009 17:19:25 -0500, salty wrote:
>>> Run a line parallel to the existing markers but outside the wooded
>>> area. Then from any point you like on the reference line, measure
>>> perpendicular into the woods the same length as the offset of the
>>> outside line from the end markers.
>>
>> Aha - yes, that's a good plan. There are really too many buildings on our
>> side of the line to do that, but I can do it from the vacant plot (the
>> folk who own it currently are good enough that I know they won't mind)
>>
>
> Since the lot next door isn't wooded, that's your solution.
Well, the wooded area does extend maybe 100' into the next-door lot, but
that's not too bad I think. I suspect if I do that to get my line close
(it might wobble a bit) I can straighten it up once it's 'drawn'.
> If you do end up having to chop any sight lines, it will be a lot easier
> if you can wait until winter after all of the leaves have fallen off the
> trees.
Uh huh. Of course if I were to put a fence through I'd need to do
some chopping anyway :-) But I'll hold off on the fence as it depends who
buys the lot (which may end up being us anyway) and it seems a shame to
clear a path if it's not needed. Our dogs sometimes wander onto that lot
though which is the only reason I might decide to fence it.
cheers
Jules
re: "so what's the point?"
The point is that this is a DIY group. ;-)
Money is not the point - it's the thrill of the fight!
Kill two birds...
Save some money and figure out your lot line at the same time:
Just buy the wooded area that extends into the next lot.
I looked up some directions the other day on Google. I normally use
mapquest, so Google dir. was new to me. I clicked on one of the camera
icons, out of curiosity, and....lo and behold...there I was, the day I
worked on putting some Bondo on the old Buick in front of the house :o)
You would hold the GPS over each marker and record the latitude and
longitude coordinates. Then the simplest way to compute the intermediate
points is too select, say the mid-way and quarter-way points. You use the
average of the coordinates for the midway point and then the averages of
the midway and end points to get the quarter-way points. Then just walk
along the line until the GPS says you are on the quarter-way and midway
points. Pound in stakes there. It will be within a view inches accuracy.
You can greatly simplify the math if you set the GPS to use decimal
degrees instead of degrees/minutes/seconds.
GPS does need a clear view of the sky to see the satellites. It won't
work when the leaves are thick but it should see through the trees when
the leaves have fallen. So from now to spring is your window of
opportunity.
Note that you must keep the GPS within clear view of the sky tyhe whole
time. You may lose the relative accuracy if you put it in the car and
drive to the next marker. Again, you can test this by driving between the
markers - if it finds each marker the second time with the accuracy you
need then it is fine, if not, get out and walk.
So if you rented the GPS *and* the guy who knows how to run it at the
same cost of as simply having the survey done, would you not be out in
the woods holding the GPS with the guy looking over your shoulder
(making sure you used it correctly)?
I know I would be. My curiousity would make me do it.
OK, we're picking the proverbial nit here, but your deck analogy
doesn't match the situation I described.
You used "following the deck guy around" and I said the "GPS guy was
looking over my shoulder". I would be doing it myself, but with his
guidance, just as if I was holding the screwgun and the deck guy was
telling me where to put the screw.
As far as "guessing" that they would charge more to let me help, keep
in mind my original premise: I rented the GPS and the guy for the same
price as getting the survey done. I wasn't suggesting hiring the
survey company and then insisting that they let me help. This is a
"side job".
Assuming the GPS was actually available for rent (and that may be the
biggest obstacle) then it's extremely possible that the "guy" would be
willing to make a few extra bucks on a Saturday afternoon by doing
some free lancing. This is not such a far fetched premise. The GPS
owner makes money on his GPS when it would otherwise be sitting on a
shelf * and the "guy" makes some extra pocket cash.
* I went to a 40th birthday party that was staged as a funeral (the
end of the guy's "former" life). They paid a funeral home $50 to park
a hearse in the guy's driveway during the party. It was a Friday
night, the hearse wasn't being used, so the funeral home made a little
money on an asset that would have been idle.
I don't know the system surveyors use but the aforementioned FSA (Farm
Service Agency) system works in one of two ways.
To lay out a field they start by downloading waypoints into a handheld
device and then all they do is find the point(s) where the device
registers a null deviation.
The specific points include all boundary corners and the (I presume
internal) software provides the target for straight line(s) between
those points.
Alternatively, the field technicians survey fields by simply driving to
the boundaries of the area planted, say, and at each corner and along
the way every so often "mash a button" and that records a set of
coordinates. These are then uploaded from the device and converted into
maps and acreages, etc. back in the office.
Doesn't seem much to it altho I've not actually pushed the buttons I'd
presume their systems are similar.
Somebody else mentioned the 5cm/2in precision -- seems like I'd heard
that kinda' numbers before but not positive whether that's really so for
absolute position or only for relative. As noted above the quite-pricey
(at least for DIY use) auto-track ag systems are about twice that. Of
course, there's a lot of ancillary stuff besides the GPS system in those
and impossible to back out what that alone would be. But, the software
systems supporting it aren't giveaways I'm sure despite the fact it
doesn't cost anything to duplicate there're non-insignificant
development costs to amortize there...
--
Running a line between two end points that are equally offset from the
corners should work fine. Just measure back the offset amount
anywhere along the line to get the actual boundary. I have done it a
number of times and come within a couple of inches of where subsequent
surveys showed the boundary to be.
> We've got a bunch of woodland that's partly on our property and partly on
> a neighboring (vacant) plot. Runs for about 300' or so, and there's a
> boundary marker either side of the woods.
>
> I'd quite like to add a few more markers within the trees, just so we know
> where the boundary is (and maybe fence at a later date) - question is, how
> to mark it out? The woodland's too dense to see through to the other side,
> even at night with a flashlight on one of the markers, so I can't just
> walk and "home in" on it.
>
> I'm not sure that GPS is accurate enough to do it that way - any other
> clever tricks?
>
> Did wonder about running two lines, meeting at one of the markers. All I
> need to do is get them straight through the trees (which might be a
> challenge in itself) - then I can presumably measure distance from each
> to the other marker at the far end, translate that to a scrap of paper,
> and calculate where the "true line" is between the two markers for any
> given distance along one of my guide lines. Does that make sense? Maybe
> there's a simpler way, though...
>
> Ideas on a postcard, or on usenet, whichever is easier.
>
> cheers
>
> Jules
A quad-fifty, mounted on the back of a half-track for stability, will
mow a nice straight line through trees and all.
What? You think it needs to 'see' the satellites?
As a matter of fact, it does need a clear shot. The signal from the
GPS satellites is not very strong, and leaves on trees is often enough
to disrupt communication with a GPS receiver. Heck, even satellite TV
dishes have trouble with leaves between them and the satellites they
use.