Fast Tip-Tilt Segment Alignment For Segmented Mirrors

A method for fast identification of segments and alignment of the segmented mirrors has been developed and applied for the deformable mirror of the WHT AO system (NAOMI) and for the GTC 36-segment primary mirror. By moving each segment by a known but different amount and in a different direction it is possible to identify many segments simultaneously using a pattern-matching algorithm which finds spots that have moved by a segment-specific vector from one image to another. The method does not need any special optical setup. The applicability of the method for the segmented primary mirrors of future telescopes is discussed.