Method of and apparatus for optically determining positions and orientations of mirrors

A method of optically determining positions and orientations of a plurality of mirrors in a field of view of an objective, the method comprising:

• illuminating the field of view with parallel light rays;
• arranging a first camera in an image plane onto which the objective images the field of view;
• arranging a second camera in a focal plane of the objective;
• taking a first picture with the first camera and a second picture with the second camera at a same point in time;
• arranging a third camera in an intermediate plane located at distances to both the image plane and the focal plane of the objectives;
• taking a third picture with the third camera at the same point in time as the first and second pictures are taken with the first and second cameras;
• determining the positions of the mirrors in the field of view from positions of light spots in the first picture;
• determining the orientations of the mirrors in the field of view from positions of light spots in the second picture;
• and
• determining which of the orientations belongs to which of the positions of the mirrors in the field of view by correlating positions of light spots in the third picture with both the light spots in the first picture and the light spots in the second picture.