ABSOLUTE COORDINATE ACQUISITION METHOD

An absolute coordinate acquisition method is an absolute coordinate acquisition method for acquiring absolute coordinates of an underground pipeline, the method including: a marking step S of setting a plurality of reference points on a road surface and setting a measurement point on a pipeline installed inside an excavated ditch; a measurement step S of measuring absolute coordinates of the reference points; a relative position calculation step (S to S) of calculating relative positions of the reference points and the measurement point to a reference position; and an absolute coordinate calculation step S of calculating absolute coordinates of the measurement point based on the absolute coordinates of the reference points and the relative positions of the reference points and the measurement point.