Star Mapper geometric calibrations

The star mapper geometric calibrations determined the position and orientation of the star mapper slits with respect to a fiducial reference line on the main grid. The calibrations covered the effective basic angle correction, which, due to projection effects and slight differences in focal length for the two telescopes, is not identical to the basic angle as applicable to the main grid. Also shown are the position correction for the chevron slits (see image below), the correction to the orientation angle of the entire slit group, and the correction to the vertical slits position.

SM chevron slits