Indirect position determination with the aid of a tracker

A method for indirect determination of a point position (P) and/or a surface orientation in a point position with the help of a tracker (1) and with the help of a measuring device (2), the measuring device (2) comprising a retro-reflector (3) as a target point for a light beam emitted by the tracker (1) and a reference point (R), said method comprising the steps of:

• positioning the measuring device (2) in a region of the point position (P) such that the reference point (R) of the measuring device (2) and the point position (P) assume predefined relative positions and such that a direct line of sight connection exists between the tracker (1) and the measuring device (2),
• positioning the target point of the measuring device (2) in a starting position (3.1),
• detecting the target point of the measuring device (2) in the starting position (3.1) with the tracker (1),
• determining the starting position (3.1) of the target point by determining a direction and distance between the tracker position and the target point,
• moving the target point away from the starting position (3.1) along a trajectory path (A) exactly defined relative to the reference point (R),
• following the moving target point with the light beam,
• recording changes in distance and direction between the tracker (1) and the moving target point, and
• on the basis of the determined starting position (3.1), on the basis of the trajectory path (A) of the target point tracked by the tracker (1), and on the basis of stored values concerning the trajectory path (A) and the relative arrangement of the trajectory path (A) and the reference point (R) and the relative arrangement of the reference point (R) and the point position (P), the position and the orientation of the measuring device (2), calculating the position of the reference point (R) and the point position (P) and/or the surface orientation in the point position (P).