Rectification of a laser pointing device

A method for establishing the position of a laser pointing device relative to a plurality of fiducial points each having a precisely-known location, the method comprising the steps of:

• providing an optical device for detecting perpendicularity of a beam to a plane in a known angular relationship to a coordinate system of said fiducial points;
• selecting a point in said plane at which the beam of said laser pointing device is to intersect said plane;
• and
• adjusting the spatial position and angular orientation of said laser pointing device relative to said fiducial points so that said optical device detects said perpendicularity when said beam is aimed at said selected point.

An apparatus for rectifying a laser pointing device that aims a laser beam by deflecting said beam through a plurality of optical deflection devices each directed by a galvanometer controlled by an input, the rectification apparatus comprising:

• an array of spaced-apart fiducial points, each having a precisely-known location relative to the other fiducial points;
• an optical angular detector device having a selected location and angular orientation with respect to said fiducial points, and configured to detect a laser beam directed at a selected angle at a selected point;
• a mounting gantry configured to position the laser pointing device at a selected height with respect to said fiducial points, and to aim the beam at said selected point at said selected angle, thereby triggering detection of said laser beam by said optical angular detector;
• a control configured to carry out the steps of:
• calculate nominal galvanometer inputs needed to aim the laser beam at said fiducial points assuming no error internal of said laser pointing device or in said established position and angular orientation;
• measure actual galvanometer inputs that aim the laser beam at said fiducial points;
• determine the angular errors internal of the laser pointing device by comparing said actual galvanometer inputs to said nominal galvanometer inputs;
• and
• store said determined angular errors in a form for use in converting nominal galvanometer inputs computed by a control to actual galvanometer inputs to compensate for said internal errors of said laser pointing device.