Experimental study on the measurement of convex hyperbolic mirrors with Hindle and stitching methods

It is a difficult work to measure the large convex surfaces. However, as the secondary mirrors, the convex aspheric surfaces have been to several meters in diameter to meet the giant telescope. In this paper, the method for testing the large convex hyperbolic mirror with Hindle and stitching methods were introduced. Two experimental demonstrations were provided by testing a convex hyperbolic. The first experiment for testing the convex hyperbolic mirror is 8 subapertures testing in one ring. In the secondary experiment, the convex hyperbolic mirror was divided into two rings to be tested. By comparing the results of this testing method with the QED measurement results, it is shown that the both of the stitching results are in good agreement with the QED measurement results.