Ground Control Points are used to lock your Site Scan data into the local coordinate system. Without GCPs, the orthomosaic will likely be several feet off. However, Site Scan Manager allows you to reference your orthomosaics with GCPs to bring the accuracy down to an inch or two, allowing you to check the placement of forms before pouring concrete, trenchwork before laying pipe, and beams before fastening down. GCPs also persist throughout a Project so they can be used to check the accuracy of any job or overlay.
To add GCPs, follow the steps below:
Note: The units of the GCPs correspond to the reference system of the Project. Here, we see Easting and Northing in US Survey Feet because I selected California State Plane Zone 3.
Note: GCPs typically come from survey firms in either a table or document like the one below. If you are having trouble deciphering GCPs, contact Success Services at firstname.lastname@example.org and we will be happy to help.