Coordinate Systems For Projects

Working with Coordinate Systems is typically the realm of the Surveyor, however in construction projects, whether we are an Estimator or 3D Modeler or a field surveyor, we have to get the coordinate system information correct if we want to

  • Turn on the background image / street map in TBC
  • Export data to Google Earth as an overlay
  • Export to field systems for use in Machine Control or field survey

Getting a good understanding of Coordinate Systems and how to read the data provided for the project, how to enter the data into TBC in order to facilitate all of the above requirements is going to be an important skill to learn.

In this example, the user was provided a LandXML file in the “Project Datum” which is shifted to the N and E by 100000m according to the plans. So to get the LandXML to line up with the background map system of TBC you have to shift the map base to line up with the project data (as defined in the Project Datum).

To do this you will use the LocalSiteSettings command and apply the Shift as a negative value i.e. -100000m and -100000m and that will convert it into US Feet and that will then cause the provided project data to line up with the TBC background Map / Image service. In addition, now that you have got things lined up correctly you can also export data to Google Earth for downstream presentation purposes etc.

Hope you find this helpful

Video Shows you how

If you want to try this yourselves - here is the provided project data that I was working with in the video

LandXML File
B-C-MERGE.xml (3.9 MB)

PDF File with Coordinate System Information
SR3 MP32-35ProjDatumCalc-Ad02.pdf (202.4 KB)