Method and apparatus for determining the location of points on a three

Abstract

This invention discloses a method and an apparatus in which coordinates of points on a plurality of sections of a three dimensional thing are measured based on a plurality of different coordinate systems and then transformed into those in a single reference coordinate system. The coordinates of the section adjacent to the reference section are transformed into coordinates in the reference coordinate system which is used to measure the coordinates of the points on the reference section through the following processes: measuring the coordinates of at least three reference points on the overlapped portion between the reference section and the adjacent section based on the reference coordinate system and the second coordinate system which is used to measure the coordinates of the points on the adjacent section; determining the positional relation between the two systems above using the measured coordinates of the reference points; and then, transforming the coordinates of the points on the adjacent section defined by the second coordinate system into those in the reference section using the above positional relation. The coordinates of points in the other sections are subjected to similar processes to express them in the reference system.