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Fixing wrong cords on control point
Posted by glasscake on July 17, 2023 at 8:20 pmalight, real stupid mistake, I have 2 control points: (Easting,Northing) 1000,5000 & 889,5279 (rounded).
did my setup in survey pro, and fat fingered point 2 to be “899” instead of “889” now I have a control network inside my building that are all wrong.
Please tell me there is an easy way to resolve this without having to reshoot all my points (150)! I have Autocad, Civil 3D, Survey Pro, excel as available software.
lurker replied 1 year, 1 month ago 14 Members · 20 Replies -
20 Replies
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Should also note this is an open survey so everything was based off these two control points.
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To the surveyor coordinates are not data. They are the product of data. When you collect total station data you are collecting horizontal angles, zenith angles, slope distances, and measure ups. The data collector uses that data to calculate coordinates. So, yes, there is a way to take that data and compute new coordinates based on a different starting point.Â
*** Before I go on – you should have checked the distance to your backsight before you proceeded. That would have alerted you to the problem at the start. That’s just good practice. The ways of the blunder are many, and varied. ***Â
Personally, I use Star*Net to do this. Its so easy that I frequently pay little attention to the control coordinates until I get the data into that format. But you didn’t list StarNet as one of your options.
So I’m going to recommend that you enter the coordinates you have into a Civil3d drawing and translate/rotate them onto the correct orientation (based on your two correct coordinates)Â using the ALIGN command. Sort of a blunt force approach, but effective and simple.
Another option -works with some data collector programs, not sure if Survey Pro is one of them – is to edit your busted coordinates in the raw data editing function of the dc and letthe software recalculate the coordinates. Worth a try (after you have backed up the data you have).
Third option –Â Civil3d is supposed to be able to calculate coordinates from raw data, although I’ve never actually met anybody who can successfully do it. Its there but I couldn’t begin to explain how it works.
Forth option – get busy with your calculator and/or excel and calculate coordinate the old fashioned way from the raw data.Â
I should think that your supervising LS would be able to help you with this. It is a very common problem.   Â
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Like Norm said: back up all your data; good, bad, or indifferent…
Then I would use at least 2 of the methods he recommended; just for redundancy.
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I hope everyone has a great day; I know I will! -
Change the set up info in Survey pro to the correct coords and it will recalc the resulting shots. Without finding the blunder in your backsight check, I’m curious how you did find it?
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@norman-oklahomaÂ
As a first pass in autocad I placed a point of my correct cord first I rotated my dataset to align with it then I moved the dataset linearly to the good point. Seems to be OK. ill double check with Civil 3D later.
I might be missing something but I edited the raw data for my bad control point 2 to match but that does not do a recalc and all of the additional points have the same position before the edit.
When I initially tried to do a station setup with two known points I got an error saying my deviation was too great. Unfortunately I did not look into it further and instead did a setup with 1 known point on the bad point back sighting the good point. No error popped up at that point in time, not sure why i would assume the deviation would still be an issue
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As a first pass in autocad I placed a point of my correct cord first I rotated my dataset to align with it then I moved the dataset linearly to the good point. Seems to be OK. ill double check with Civil 3D later.
That’s OK, but the ALIGN command does both of those functions in one step. This manner of data adjustment is very common and the results will be fine. I prefer not to go this way because there is no paper trail.Â
I might be missing something but I edited the raw data for my bad control point 2 to match but that does not do a recalc
Did you just edit the point, or did you edit the raw data? I’m not sure if this works in that software or not, but I’m sure that you would need to make the edit in the raw data editor to have a chance.
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@glasscake That is scary. Error on e but not 2nd time. I only remember survey pro when it was TDS in a hp 48. I did use a recon a few days once helping a friend on a weekend. I can still remember that distinctive sounds of solving the set up and that chirping type sound when you took a shot. Now days my hearing is so bad i hear nothing. For fun take that excell spread sheet solve for the correct azimuth take your raw data angles distances and compute the rest and lat and departure then solve your coordinates.  Just do your open end traverse and a few points and check against the cad civil 3d.  I am no expert in civil 3d but didn’t auto cad have a way years ago to type in all angles distances like from a field book entry. And it would solve for the coordinates. Maybe i was using C&G or some survey plug in back then. I just remember we entered all our information from field book and then some random topo shots from each set up to check our comps.  We didn’t have a data collector all the time.
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@glasscake You can’t just edit the point’s coords. You have to go into the raw data and change the coords entered there to the correct ones. This will recalc all of the coords for that set up. If you have subsequent set ups based on the bad coords, you have to go and change the raw data entry to the correct coords for each set up. Example you have bad coords for the 1st set up and traverse through 8 other points/setups. Even though you fixed the 1st set up raw data coords, Survey pro will not put the correct coords for the 2nd set up in the raw data. You have to edit each subsequent set up. Editing it in the coordinate file will have no effect. It must be edited in the raw data file for each occupied point.
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I would speak to the surveyor supervising this project. Folks here gave a lot of great advice on the technical aspects of solving this problem, but I still think you should talk to your supervising surveyor about this.Â
He or she will show you how THEY want it fixed, and what records to create and notes to make.Â
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When I initially tried to do a station setup with two known points I got an error saying my deviation was too great. Unfortunately I did not look into it further and instead did a setup with 1 known point on the bad point back sighting the good point. No error popped up at that point in time, not sure why i would assume the deviation would still be an issue
Huh? I’ve only very briefly used surveypro and my memory is foggy, but this isn’t making sense to me. It sounds like it warned you your backsight was bad, but for whatever reason you went ahead with the setup.
I remember surveypro being somewhat unintuitive when I used it, as in… you shoot your backsight first and then tell it your HI/HR and maybe even what points you’re using or something goofy. Anyway, I would suggest getting some training on the software before a blunder like this burns you.
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May I suggest for future situations where there is the slightest hint of a deviation in your back sight check routine that you store a point on your back sight as a check in addition to comparing distance measured to inverse. Stuff happens. If you brain fart and transpose your occupy point and BS point, the distances will check the same.Â
Everything you need to recalculate is in the raw data whether you do it using SP or your calculator.
Willy -
Unless you’re staking out that day, there’s nothing to worry about. Change the coordinates in your raw file when you go to process the file. Everything will be great.
If you’re one of those who like to import a txt or csv instead of processing the raw, rw5, then you or your supervisor should use this to learn how to process/run/import them. This is good, especially if you haven’t been doing linework, and will have an opportunity to learn how.Â
That said, you obviously can do linework using just a coordinate file too, in Carlson, not sure about C3D. Good luck
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AMEN
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*** Before I go on – you should have checked the distance to your backsight before you proceeded. That would have alerted you to the problem at the start. That’s just good practice. The ways of the blunder are many, and varied. ***Â
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The ways of the blunder are many, and varied.
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Now I have to make a new sign to hang in my office.
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The Align command in Civil 3D is one of my favorites. If you setup on 1 and BS the bogus 2, you should just have a rotational error. If you resected off those two, good luck!
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not sure why i would assume the deviation would still be an issue
Any time you constrain yourself to 1 point there is no way to detect a blunder, that is why it didn’t give you any warning.
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I would speak to the surveyor supervising this project. Folks here gave a lot of great advice on the technical aspects of solving this problem, but I still think you should talk to your supervising surveyor about this.Â
He or she will show you how THEY want it fixed, and what records to create and notes to make.Â
It should be the first place employees go. I couldn’t succeed as a mentor if those under my supervision went to the internet instead of me.
Â
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Thanks all for the useful info.
I’m just a hobbyist and this project was for my building at work. All I have for the building are outdated AutoCAD drawings with wrong dimensions. The hope is to remeasure out specific sections of the building when I add new equipment. (ran into an issue the other day by trusting the drawings which were so far off I lost 4 feet of bench space)
So no supervisor to help me and I’m self taught through manuals and Rami Tamimi’s YouTube series lol. I think my rotate and move linearly in AutoCADÂ is giving me the correct results. One of these days when its slow Ill go back out to the monuments and reshoot my traverse and my control points inside the building. Then if I get different measurements IÂ can align from there.Â
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not sure why I would assume the deviation would still be an issue
Any time you constrain yourself to 1 point there is no way to detect a blunder, that is why it didn’t give you any warning.
Wouldn’t the horizontal distance be different? or during known point setup is it just setting the azimuth?Â
The Align command in Civil 3D is one of my favorites. If you setup on 1 and BS the bogus 2, you should just have a rotational error. If you resected off those two, good luck!
I tried the realign but since I put in the wrong easting the distance is incorrect from my expected points. either way I think the rotate and move is working correctly
@glasscake You can’t just edit the point’s coords. You have to go into the raw data and change the coords entered there to the correct ones. This will recalc all of the coords for that set up. If you have subsequent set ups based on the bad coords, you have to go and change the raw data entry to the correct coords for each set up. Example you have bad coords for the 1st set up and traverse through 8 other points/setups. Even though you fixed the 1st set up raw data coords, Survey pro will not put the correct coords for the 2nd set up in the raw data. You have to edit each subsequent set up. Editing it in the coordinate file will have no effect. It must be edited in the raw data file for each occupied point.
I think I may have done something wrong in Survey Pro then. In SP I go to “View/Edit Raw Data” then go to the “Key in” for my bad control point, right click point and “edit point data” put in the correct cord and there is no change. I also tired “Fix Station Setup” under “adjust” and when I did that it said no points were reliant on my bad control point?
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Huh? I’ve only very briefly used surveypro and my memory is foggy, but this isn’t making sense to me. It sounds like it warned you your backsight was bad, but for whatever reason you went ahead with the setup.
To be honest I was rushing and I didn’t read into why the warning was showing up. I just assumed (ass out of u and me) the deviation was because I put in an elevation of 100 for each monument because supplied docs did not have elevation.
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Wouldn’t the horizontal distance be different? or during known point setup is it just setting the azimuth?
If you told it to use 1 point and an azimuth, there is no distance to compare to. The only way the data collector program is getting a distance to compare is by inversing the 2 coordinate pairs. If you use 2 points it will calc the azimuth and the distance between the 2 points. When you use only 1 point there is not a distance to another point, only an infinite direction.
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