AUTO CENTRING LEVELLING

The invention relates to a surveying system comprising a surveying instrument, a control system, a tilt measuring system, a levelling unit, a camera system, a second distance meter, wherein the control system is configured for at least one of receiving and determining an image position of a captured image, the image position corresponding to a location on the ground, effecting the levelling unit to adjust a tilt status of the surveying instrument, based on the image position, until a first tilt status is obtained, the second distance meter aiming onto the location on the ground in the first tilt status, effecting the tilt measuring system to determine the first tilt status, storing the determined first tilt status, effecting the second distance meter to measure a distance to the location on the ground, storing the measured distance to the location on the ground, effecting a first angle encoder of the surveying instrument to measure a rotatory position of a support unit of the surveying instrument, storing the measured rotatory position of the support unit, effecting the levelling unit to adjust the tilt status, based on sampling the tilt measuring system, until a second tilt status is obtained, the yaw axis being aligned with the gravity field in the second tilt status, calibrating a preconfigured centre point of the surveying instrument based on the distance to the location on the ground, a deviation between the first tilt status and the second tilt status, the rotatory position of the support unit.