I am lead to believe Topcon GPS users may only calibrate for elevation on three, or is it four, control points to establish a localised level datum and that the result is an inclined plane of best fit between the control points. I am also lead to believe the option to maintain a "constant adjustment" is not available as it is with Trimble stuff. What happens if one or two of the points is in error vertically or if these "one or two" points were not officially issued as "control"? Answer..."it" hits the fan.
Surely Topcon provides the option to create an horizontal datum plane by adopting only one point for level and other points would be used as checks only. I sure hope it does if I ever have to use Topcon.
Can anyone enlighten me while I do a bit of a clean up!