Trimble Business Center is designed to incorporate and process not only GNSS data, but also digital level data, and conventional total station data.
In a situation where a project consists solely of GNSS data, i.e. where no leveling or total station data was observed, is it appropriate to use the Survey>Adjust Network tool? I just tried it, and it seemed to yield results, including the display of error ellipses for each point.
I'd appreciate any suggestions. Thanks.
Absolutely. You have to make sure the right coordinates and elevations are being held, which takes some getting used to, trial and error to figure out. For example to add a known orthometric height you have to go into the add grid coordinate dialog. You can add a known ellipsoid height in the add local or add global dialog (not sure what the difference really is).
But be aware that it only adjusts observations with redundancy. The points with no redundancy get computed under project->compute project (or F4). One could argue (correctly) that there is no adjustment possible for observations with no redundancy. But, I like the way Geolab, for example, does it. All observations are "adjusted", so that a spur line (sideshot) gets computed with the latest adjusted coordinate of the standpoint. I imagine the final results are the same, but I am always worried that I will forget to press F4 after an adjustment, not sure if TBC does it automatically.
I should add that I am still learning TBC, and I still use Geolab for the final adjustment, I am just more comfortable with the process and the results.
Thank you, John.
I'm very new to TBC, and new to GNSS post processing in general, so I appreciate you helping me along. I had found the TBC Help menu, and it presents much more detail than just the tutorials alone.
One follow up question, if I may. If I use the Internet Download option to import GNSS data from surrounding CORS stations, then that would have a tendency to create redundancy and thus improve the network solution? With CORS stations in my area at 20 km or more, the residuals of the baselines appear to be rather large, but if I used four surrounding stations, all with simultaneous data for the observation period, it seems that would create quite a bit of redundancy.
It does, although some (many?) would argue that it is still a single occupation, and therefore not redundant. However, the fact that you have four different sets of fixed coordinates does make it subject to adjustment. In my opinion you do have redundant observations due to the fixed coordinates at the CORS, although not "as redundant" as if you tied it in two separate sessions.