Geodimeter 120
BTW, for a blast from the past, here's a link to a photo of the setup that the 1981 surveyor may well have been using, a Geodimeter 120 on a Sokkisha 1-second theodolite.
Geodimeter 120 on Sokkisha theodolite
Geodimeter 120
So he attempted to radially stake out a calculated corner position from a random control point and missed by 500'. Just the fact that it is 500' short and on close to the correct azimuth from the control point pretty much confirms it but the vertical information helps too obviously.
I agree that the 500' problem is clearly a blunder.
An edm will not likely bust an even number of feet- it would be an even number of meters.
But I think the question still hanging around the thread is how ten dollar an acre land gets enough attention from a court or client to send you out so far afield as an expert witness (I think that we can stipulate to your qualification). I'm thinking that your fee has be be well above the value per acre. Maybe I misread the intent of your comment. Is it actually ten dollar an acre land, or is it maybe worth ten dollars per year to a cattleman for a grazing lease?
As greasewood flats with an occasional ocotillo, it's pretty well down the list as grazing land.
It looks like a fascinating survey. I'm just wondering how it came about. And I understand that there may be some things about this that you cannot discuss just yet.
Geodimeter 120
> So he attempted to radially stake out a calculated corner position from a random control point and missed by 500'. Just the fact that it is 500' short and on close to the correct azimuth from the control point pretty much confirms it but the vertical information helps too obviously.
Yes. I consider it to be nearly a certainty in that case. The question itself is more of a novelty, but it's a reminder of what sorts of gross blunders careless radial stakeout made possible before the belt-and-suspenders of data collectors/field computers and electronic logging of measurements.
Interestingly, that 1/2-inch iron rod in a rock mound was just some unexplained mystery until I finally saw the 1981 surveyor's field book.
> But I think the question still hanging around the thread is how ten dollar an acre land gets enough attention from a court or client to send you out so far afield as an expert witness (I think that we can stipulate to your qualification). I'm thinking that your fee has be be well above the value per acre.
Yes, my fee will probably be enough to have bought 1/5 of those 600 acres at the price for which they sold in 2000 (a good bit more than ag value). The lawsuit involves a claim for damages in excess of $100k. That gets everyone interested in some answers that otherwise would probably just fall by the wayside. Stuff gets held under the microscope.
Geodimeter 120
> BTW, for a blast from the past, here's a link to a photo of the setup that the 1981 surveyor may well have been using, a Geodimeter 120 on a Sokkisha 1-second theodolite.
>
> Geodimeter 120 on Sokkisha theodolite
Just as a footnote, it wasn't until I saw that photo of the EDM mounted on the telescope instead of the standards of the theodolite that the zenith angles the 1981 surveyor recorded made sense. They were all F2 Zeniths, i.e. 360°-Zenith Angle. With the EDM on the telescope, measurements on both faces weren't possible. Since the EDM mounting lugs were evidently on the bottom of the telescope, the "pointer" or collimator being on the top of it, F2 was the zenith angle that got measured.
Geodimeter 120
> Just as a footnote, it wasn't until I saw that photo of the EDM mounted on the telescope instead of the standards of the theodolite that the zenith angles the 1981 surveyor recorded made sense.
I always hated to see scope-mounted EDMs. It was bad enough sticking several pounds of equipment on the standards of a T-1 or T-2, but loading them onto the small-diameter scope bearings seemed like an egregious mechanical insult. The advent of the total station undoubtedly brought forth sighs of relief from many an optical gun.
Geodimeter 120
> I always hated to see scope-mounted EDMs. It was bad enough sticking several pounds of equipment on the standards of a T-1 or T-2, but loading them onto the small-diameter scope bearings seemed like an egregious mechanical insult.
Yes, that configuration also explains why the horizontal angles were taken on one face only, which is pretty amazing considering the distances over which they were staking out. This is just one of the stories that I may yet dine out on. "I remember in nineteen-ought-eight-one ..."
lol...that's pretty cool!!
> lol...that's pretty cool!!
Yes, in his survey work, he'd apparently determined the coordinates of some features on some pilgrimage chapels in the mountains South of the Rio Grande in Mexico and had used those to compute backsight azimuths for his stakeout from various control points. I didn't see anything systematically wrong with his results from that method. They should have worked fine, in theory. Many things work fine ... in theory.
You can easily see 50 miles on a clear winter day in the Mojave Desert. Look for the lenticular clouds; those are an indicator of severe clear conditions.
I don't know if you could make a sight that far but 5 miles would be no problem at all.
> You can easily see 50 miles on a clear winter day in the Mojave Desert. Look for the lenticular clouds; those are an indicator of severe clear conditions.
>
> I don't know if you could make a sight that far but 5 miles would be no problem at all.
The 1981 surveyor had been clever in choosing objects to locate by triangulation that he then used for backsights. His backsights were at the tops or ridges of mountains about six miles off or so (in Mexico), with the line of sight elevated so far above ground level that the normal Summer turbulence from convective heating wasn't nearly so large a factor in the seeing as it would have been at ground level or near to it.
Kent - I didn't think you'd want to discuss the particulars of the case now but didn't you mention that that the actual corner 500 away was staked years ago? Is somebody trying to claim that the 500-foot-blundered corner is valid?
Stranger rulings have come out of the courts where 30-year-old blunders relied upon by jack rabbits have come to define legal boundaries.
> I didn't think you'd want to discuss the particulars of the case now but didn't you mention that that the actual corner 500 away was staked years ago? Is somebody trying to claim that the 500-foot-blundered corner is valid?
Uh, no. That is just one interesting part of a fairly complex puzzle.
can I still
Is a private citizen able to buy unpatented land in Texas,atill?
can I still
> Is a private citizen able to buy unpatented land in Texas, still?
There are still tracts of land that were surveyed as School Land (i.e. were segregated from the public domain for the benefit of the Permanent School Fund) that remain owned by the State. I don't know the details of how one might apply to purchase them, but I'll bet the General Land Office can tell you.
Access is something to pay attention to, of course, as is whether corrected field notes will be required for patent. Those can cost pretty significant amounts of money to produce.
Geodimeter 120
Hi Jim,
You're right of course about telescope mounted EDM's but many of the trunnion axes were of steel and as EDM's got smaller the load lightened. At the time the compromise was a godsend for your average surveyor particularly over other forms of distance measurement. Have a look at the Hp 3810a or the Geodimeter 700 series-the poor old tripod was lucky to withstand the load or look at the Wild Di-3s and what that was doing to both tribrach & tripod. Not forgetting the Zeiss Elta 14 Total Station weighing some 50 odd kg!! - but that was back when surveyors had one "Popeye" right arm & well before they started eating quiche!!
MapTack
A Puzzle from 2011?
Notice the year 2011?
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:-/
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Map track posted to the thread yesterday, which bumped it to the top Keith.