Patent ID: 7859655
Filing Date: 2010-12-28
Classification: G01C,G01S

Abstract:
1. A method for determining a position of a point of interest on a surface of a target object having a target object coordinate system using a pointing instrument having an aim point axis and having an instrument coordinate system, wherein the method comprises: a) measuring an orientation of the aim point axis in the instrument coordinate system when the aim point axis of the instrument is in turn aligned with each of three calibration points on the surface of the target object, wherein positions of the three calibration points in the target object coordinate system are known; b) measuring a distance substantially along the aim point axis from the instrument to each of the three calibration points; c) calculating a calibration matrix which transforms a position defined in the instrument coordinate system to a position defined in the target object coordinate system using at least the measured orientation and distance in the instrument coordinate system corresponding to the three calibration points and the known positions of the three calibration points in the target object coordinate system; d) measuring an orientation of the aim point axis in the instrument coordinate system when the aim point axis of the instrument is aligned with the point of interest; e) calculating a position of the point of interest in the target object coordinate system using at least the measured orientation of the aim point axis in the instrument coordinate system corresponding to the point of interest, the calibration matrix, and at least one of a distance substantially along the aim point axis from the instrument to the point of interest and a model of the surface of the target object in the target object coordinate system; and f) storing the calculated position.