On Using 3D Support Geometries for Measuring Human-Made Corner Structures with a Robotic Total Station.

Performing accurate measurements on non-planar targets using a robotic total station in reflectorless mode is prone to errors. Besides requiring a fully reflected laser beam of the electronic distance meter, a proper orientation of the pan-tilt unit is required for each individual accurate 3D point measurement. Dominant physical 3D structures like corners and edges often don't fulfill these requirements and are not directly measurable. In this work, three algorithms and user interfaces are evaluated through simulation and physical measurements for simple and efficient construction-side measurement correction of systematic errors. We incorporate additional measurements close to the non-measurable target, and our approach does not require any post-processing of single-point measurements. Our experimental results prove that the systematic error can be lowered by almost an order of magnitude by using support geometries, i.e. incorporating a 3D point, a 3D line or a 3D plane as additional measurements.