Patent ID: 8743376

Claim:
A surveying instrument for measuring distances and angles, comprising: a laser emitter configured to emit a fan shaped laser beam rotating around a propagation axis with a direction of rotation; a detector for detecting light of the fan shaped laser beam rotating around the propagation axis with the direction of rotation and having at least two detector elements arranged in a known spatial relation to each another for outputting a detection signal when irradiated by the fan shaped laser beam; a position determining unit configured to: obtain a first set of detection signals from the detector, determine at least one first time relation between the first set of detection signals, determine a positional relation between the detector and the propagation axis based on the at least one first time relation; and a transceiver coupled to the position determining unit for communicating with the laser emitter and provide instructions to change either the propagation axis of the fan shaped laser beam or to increase or decrease the opening angle of the light cone produced by the fan shaped laser beam.