Development of testing convex hyperbolic mirror using Hindle method based on stitching technology

The test method of Large-diameter convex secondary mirror in development process is the key to making large telescope technology. Classical means HINDLE to test using of non-aberration points needs a spherical reflecting mirror which larger than the secondary mirror several times. This new Hindle test method based on stitching technology can significantly reduce their standard mirror’s size, drop the difficulty of processing and cut down the costs. In This paper, the Hindle testing basic principles which base on stitching technology is introduced firstly, then principle of stitching and least square method. Following the parameters of inside and outside standard mirrors are derived. Then translation and rotation transformation algorithm of different sub-aperture interferometer array data is given. Finally the preliminary results of the radial stitching experiments are given. The results showed that the relative error is RMS=6.1%, PV=5.11%. With improving and perfection, this method can be used in the E-ELT, CFGT convex secondary mirror telescope test.