I have only been using TBC for a few months but have discovered what appears to be a bug. Trimble has been notified about it more than once by several people but so far there has been no acknowledgement of the problem. I thought I would post it here so others will be aware to take corrective action.
The problem is how TBC handles coordinates imported from NGS datasheets.
In TBC the user can now develop a state plane coordinate system in original NAD 83 (the default), or NAD 83 CORS96 epoch 2002 or the new NAD 83 2011 epoch 2010. If you use the default NAD 83 there is no datum transformation and the program equates the global and local coordinates the way TGO did. If you use use either of the other two realizations, TBC assumes the datasheet coordinates are global rather than local coordinates and proceedes to do a datum transformation to an erroneous local coordinate.
If you hand enter the datasheet coordinates as local values, everything is ok. So if you use the datasheet import option, be sure to check your coordinate values.
Like I said at the begining, I'm a new TBC user so please correct me if I am wrong.
John,
If you use the extended data +.xml import from OPUS, TBC recognizes the NAD83 (whatever flavor) and treats the LLh as a "Local Coordinate".
Doug
Thanks Doug
I haven't tried to import OPUS results yet. Good to hear that works.
I'm talking about the NGS data sheets.
John
You're absolutely right John, importing the data sheets or even the OPUS solutions in .txt format gives you identical Global & Local coordinates. Only the .xml files gives you the correct Global & Local IF you've set up the correct projection/epoch. Tangled web indeed!
Doug
Are you saying that you created a state plane projection in the NAD 83 CORS96 epoch 2002 datum then imported an OPUS solution in .XML format and TBC did it correctly?
If you use the default state plane projection and import the datasheet you get identical local and global coordinates. If you create a state plane projection in the NAD 83 cors 96 epoch 2002 datum, TBC places the imported datasheet coordinate in the global box and proceeds to transform an erroneous local coordinate. TBC should put the data sheet coordinate in the local coordinate box and transform a global coordinate.
I'll catch your reply tomorrow. It's bedtime for me now.
Doug
I I tried the .xml OPUS import into a project with the state plane projection and NAD 83 CORS 96 epoch 2002 datum and TBC handled it correctly just as you indicated.
At least that is one thing TBC does correctly. 😉
John
