PW0582 SUPERSEDED SURVEY CONTROL PW0582 PW0582 NAD 83(1986)- 44 54 45.71582(N) 107 10 23.21701(W) AD( ) 3 PW0582.No superseded survey control is available for this station.
Wow, I've never seen that before.
The PID is PW0582, it is the SE base point, not sure why but the datasheet shows it as third order.
Oh, but note that PW0502, less than a hundred yards north, has the same name, is 1st order, and has superseded NAD27 data. It was monumented in 1925.
Note that PW0582 was monumented by USGS.?ÿ I'm guessing it didn't have a designation or coordinates in the CGS system until it got tied in much later.
You are correct Bill, that's odd, not sure what that point is. Either RM 2 or one of the bench marks along the highway.
There is a story for that, but I don't know what it is.
SE base is a point used by everyone during the NAD27 days, it's one of the two base point for all the surveying.
It isn't a great point for GPS but I think we may have located it RTK at some point.
This is the only datasheet I've ever used for it:
The NGS provides a tool to solve the forward problem: solving for an unknown point??s given starting geographic coordinates, geodetic azimuths and ellipsoid distance here:
https://www.ngs.noaa.gov/cgi-bin/Inv_Fwd/forward2.pol
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Also the old 1984 standards and specifications document give the following tabulation of horizontal accuracy for points determined by what are now known as ??classical geodetic methods.?
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From the information that you provided, you are using two different datums (NAD83 and NAD27).?ÿ You would have to convert the NAD27 to NAD83 and that is not accurate. As far as your orthophotos not lining up, I see this all the time.?ÿ Our orthophotos are on the Grid (NAD83) and they line up when I have scale factor in the Data Collector. If you come off of two GNSS points and then traverse with a total station on the ground, and over long distances, you will come off the orthophotos significantly. In order to correct this problem, one possible solution is to get another surveyor to set GPS control on your job site. You can even get inexpensive receivers to collect data and then send to OPUS. I don't see a solution at this point by manipulating your data. I wrote an article about the Grid to Ground Correction and you can find it here if you want to read it for reference: https://www.xyht.com/surveying/grid-ground-project/.?ÿ Best of luck to you.
he didn??t make a huge mistake. He accidentally used geodetic azimuth. He found that out, used the proper grid az and the pub NAD83 position. Just a simple input error, that was apparently (to me imo) the most likely issue, in his first post. I??m sure he??s applying the proper SF. He only traversed 1200 feet.?ÿ
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Many surveyors are NOT familiar with things they do not use every day. Recently, I observed a surveyor, who was not familiar with an area he practiced in. He blundered, in procedure, and caused havoc. I have my blind spots too.
N
Traversing 1200 ft from a pub disc in SPC is not exotic. Not in the 21st c.
He had a brain fart.
@Larry Scott, brain fart @10:00 noted.
Sometimes another set of eyes is beneficial. It's even more of a problem for solo practioners.
Nate
