Patent ID: 8537216
Filing Date: 2013-09-17
Classification: G01C

Abstract:
1. A leveling instrument comprising: an objective lens having an optical axis, an object plane intersecting the optical axis, and an image plane intersecting the optical axis, wherein the objective lens is configured to image an object disposed in the object plane into the image plane; an image receiving unit comprising at least six rows of at least eight light detectors each, the at least six rows of at least eight light detectors being arranged to form a two-dimensional detector array, the light detectors being adapted for outputting signals representing an amount of light being incident on the light detectors, wherein the image receiving unit is arranged in the image plane; a mount for moving the objective lens about a vertical axis of the mount; and at least one processor adapted to determine a vertical position of the object using weighting coefficients to calculate weighted values from the signals outputted from selected ones of the light detectors, where the weighting coefficients for each of the selected ones of the light detectors depend on a lateral distance of each corresponding light detector from a diagonal of the two-dimensional detector array, wherein the two-dimensional detector array is arranged at an acute angle with respect to an image of a vertical axis of the object when the optical axis is arranged perpendicular to the vertical axis of the mount, said image of the vertical axis of the object being generated by the objective lens, the vertical axis of the object being parallel to the vertical axis of the mount.