A registration method and device for detecting the position and alignment of an object or body part in relation to a position detection system, the method arranging a reference sensor on the object or body part and/or on an image sensor unit, detecting the position of the reference sensor by means of the position detection system, photogrammetrically detecting a surface of the object or body part by means of the image sensor unit, producing a surface model of the object or body part on the basis of the photogrammetrically detected information, determining the position of the reference sensor in the surface model, and correlating the surface model with a coordinate system of the position detection system on the basis of the determined position of the reference sensor in the surface model and on the basis of the position of the reference sensor detected by means of the position detection system.
