A REFERENCE FREE CALIBRATION METHOD FOR A POINT CLOUD MEASURING MODULE COMBINED WITH A GEODETIC SINGLE POINT MEASUREMENT UNIT

The invention relates to a survey instrument comprising a single point measurement unit, a point cloud measuring module, and a computing unit. The single point measurement unit is configured to generate first measurement data comprising coordinates a point. The point cloud measuring module has a fixed pose relative to the single point measurement unit, and configured to generate a second measurement data comprising coordinates of a plurality of points. The computing unit stores calibration parameters and is configured to generate a point cloud based on the second measurement data, to merge it with the first measurement data and to detect surfaces and object edges in it. The survey instrument is configured to execute a calibration using object edges in the setting. The single point measurement unit acquire a set of single measuring points including at least two on each flat surfaces of the object edges. The computing unit derives a vertex formed by the distribution of the measuring points. The computing unit updates calibration parameters based on the alignment of the object edges and the derived vertices.