Has anyone had any problems with the geodetic traverse calculator in Carlson Survey? I'm not too familiar with it and depending on what data I enter, I get an answer that is 2 to 4 minutes different from a e-w line that was calculated by Joseph Luchini in 1968. I am missing his bearings on the meridians by about 3 seconds. His work is NAD27 grid and in varas. One of the other surveyors in the office suggest that the carlson routing is unreliable but I haven't seen any critiques on a web search that support that.
For what it's worth, he was running east from a known point setting block corners. At Lattitude N 31?ø45'32.1" with an average elevation of 4000', he was deflecting the line about 00?ø03'15" every six miles.
I haven't used the tool a lot, but out of curiosity I used it to run a geodetic traverse around a PLSS Township Plat.?ÿ It closed within reasonable limits.
I just started at?ÿ the LAT that you listed and LON 104 deg 30' and ran a geodetic traverse due East with (2) 6 mile chords.?ÿ When I annotated the bearings in GRID NAD 27 Texas Central Zone, I get a difference of 3' 8".?ÿ That seems pretty close to your listed deflection.?ÿ
In the OP, you said that you missed his bearings by 3".?ÿ Did you mean 3'??ÿ If you are worried about missing a 50 year old survey by 3", I don't think I'll be much help. ??ÿ
I use it every day and have never had any problems. Make sure you are comparing apples to apples.?ÿ Why are you using it if you are trying to match a grid survey??ÿ
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In the OP, you said that you missed his bearings by 3".?ÿ Did you mean 3'??ÿ If you are worried about missing a 50 year old survey by 3", I don't think I'll be much help. ??ÿ
In the OP, I said that I miss the calculated bearings of Luchini's meridians by an average of about 3 seconds which I consider to be a match. That is why I believe I have screwed something up to be missing the east-west bearings by about 3 minutes. I can't believe that I can get the meridians so close and be so off on the lattitudinal lines.
Are the bearings between NAD27 and NAD83 going to be that different?
I use it every day and have never had any problems. Make sure you are comparing apples to apples.?ÿ Why are you using it if you are trying to match a grid survey??ÿ
I'm not trying to match a grid survey. I have tied in the controlling monuments and I am trying to re-construct an area that is 24 miles across and 9 miles north to south. For what it's worth, there are only 20 original, controlling monuments for?ÿ the 200 sections encompassed and most are on the west block line. I have to project east and the practice in this area is to put the block corners on a line of constant bearing and then section lines are "straight" lines in between.
I agree with Luchini's construction, but I am using my traverse and monument ties so we're not going to match exactly. But, I'd think I'd be matching closer than 3 minutes on the lattitudinal lines.
....Are the bearings between NAD27 and NAD83 going to be that different?...
These are both conformal projections, so the angles are preserved. If you have agreement in the N/S, you should also have it in the E/W.
Bearings 27 to 83 should be the same if the zones are defined with the same parameters.?ÿ ?ÿ
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In the OP, you said that you missed his bearings by 3".?ÿ Did you mean 3'??ÿ If you are worried about missing a 50 year old survey by 3", I don't think I'll be much help. ??ÿ
In the OP, I said that I miss the calculated bearings of Luchini's meridians by an average of about 3 seconds which I consider to be a match. That is why I believe I have screwed something up to be missing the east-west bearings by about 3 minutes. I can't believe that I can get the meridians so close and be so off on the lattitudinal lines.
Are the bearings between NAD27 and NAD83 going to be that different?
Ok, that wasn't totally clear, but I see what you are saying now.
Carlson gives the same bearings in NAD27 & NAD83 for your area of interest.
Just a word of warning, for the 1st calculation of 3'08" I had the wrong datum of WGS84 instead of NAD27.?ÿ When I changed it to NAD27 inside the running project, it listed the same bearings after re-annotating, but when I started a new project with the NAD27 datum and performed the same calculations, it changed the bearings to a difference of 3'11".?ÿ That's not on the same magnitude of error that you are talking about, but you might want to check.