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 Adjusting Network - problem with elevations

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Panagiotis Dialiatsis's profile image
Panagiotis Dialiatsis posted 07-26-2024 00:26
Hello, i have a question about adjusting network: when i click adjust, in the report, the elevations of my points are shown as "?". That means they are not calculated. I use grid type control points, which are Northing-Easting points (fixed in 2D) and shoted benchmarks which are fixed in e (h row doesnt work because they are not local). I want to adjust my network and give elevation to my points using the e, grid-type, benchmarks. How can i fix this problem?

ian bissonnette's profile image
ian bissonnette  Best Answer

a little hard to tell without knowing a bit more information, like which points are merged to which. but i have a few suggestions. i guess the first is make sure that your elevations ties are merged to other points in the network, but likely this is already the case. also make sure that you have the settings on to perform vertical adjustment, i think it is in the network adj settings, you likely already have this as well.

i think tbc is having trouble because it has no starting point for the elevations. so for your control that you are holding only the H, try making the V "control quality" as well, for one or likely all three. this will give tbc a starting elevation. then in the network adj, the E column should then be available, but do not check it unless you want to fix it at that elevation. see if it will run the V adjustment. if it does, then it will likely throw a flag, but now you have a new computed elevation and so you can change it to what it should be and start again if you want to clear the flag, but still keep the V unchecked for those H ones.

another thing, if that does not work, you could try fixing the E on those horizontal control and then use the dropdown for each of them to assign an amount of 'float' that tbc will allow them to move. if there is some validity to the V on those coordinates then this might be valuable to do, especially if you know the quality of the initial elevations. 

hope this helps.

Ramin Rad's profile image
Ramin Rad

Check the simple stuff first—make sure Vertical Adjustment setting is turned on. It could be the quick fix you need to see those elevation values.

Panagiotis Dialiatsis's profile image
Panagiotis Dialiatsis

Of course I had performed vertical adjustment checked. What i did was to fix the E in horizontal points, just like you said, because the initial coordinates had only E,N and not elevation. For that purpose I put in properties a random elevation to them, for example 0.000, set it as control quality but NOT check it at the constraints, run adjustment again and it worked!. Thank you for your response

Robert Hoy's profile image
Robert Hoy

Are you trying to state you have elevations you'd like to use for these control points that you already have?  If so, right click over the row in Point Manager (or in the point list within Project Explorer) and choose "add coordinate" entering only the elevation and choose quality:  control.