Optimal Vertical Placement of Total Station

When using the free station method, a total station (TS) is established by performing distance and angle observations toward a number of control points (CPs). The quality of the establishment is crucial for the quality of subsequent measurements. The optimal horizontal location of the TS has been investigated in previous studies. The vertical precision also is important in many applications, especially with significant height variations. Therefore, this study focused on the optimality of the vertical location of the TS. The sum of TS coordinates and orientation variances was used as an optimality criterion. To investigate the optimization problem, an analytical and a trial-and-error method were developed. Results from both methods show that the height component has no significant influence on the optimal vertical placement of the TS. Inspection of results from the trial-and-error method, where the CPs were moved in different height layers, indicates differences in the height uncertainty of the establishment in the micrometer range, which is negligible for most engineering applications.