Patent ID: 7623224

Claim:
A method for calibrating a surveying instrument comprising a base element and a camera with an image sensor, the camera being rotatable about a vertical axis fixed with respect to said base element and being rotatable about a tilting axis, the tilting axis being rotated about the vertical axis with rotation of the camera about the vertical axis, wherein data associated with calibration points and images of the calibration points on the image sensor captured in different faces are used, the data for each of said calibration points comprising distance data representing a distance between each said calibration point and the surveying instrument and the data for each of the images of each said calibration point comprising image position data representing the position of the image of each said calibration point on said image sensor and orientation data representing a horizontal angle of rotation of the tilting axis about the vertical axis and a vertical angle of tilting of the camera about the tilting axis, and wherein on the basis of the distance data for each of the calibration points and the image position and orientation data for each of the images of the calibration points the surveying instrument is calibrated simultaneously taking into account at least one optical property of the camera and at least one of the relative orientation of the vertical axis and the tilting axis and the orientation of the camera relative to one of the base element, the vertical axis and the tilting axis.