Development of the stitch algorithm for a free-form measurement machine (5th report)

Measurement of the Non-axisymmetric Surface

Abstract

The stitching measurement, which combines plural partial measurements into a whole shape, has been developed based on interferometry. But, in the case of free-form measurement machine, a serious calculation error occurs because the measured data are sparse 3D points. For this reason, we have developed a new stitch algorithm named ARSA (Approximated Reference Shape Algorithm). This paper investigates how it works on non- axisymmetric surfaces using a simulation. The target is the primary mirror segment of TMT (Thirty Meter Telescope) whose diameter is 1.44m.