A Three-coordinate Measuring Method for the Surface Shape and Geometric Parameters of Aspheric Mirrors

As aspheric mirrors are more and more widely used in aerospace remote sensors, the detection technology of aspheric surface shape and geometric parameters has become more and more important. At present, the surface form deviation before the mirror polishing process and the geometric parameters such as the curvature radius of the mirror vertex and the off-axis amount after the mirror processing are completed are mainly performed by using a coordinate measuring machine, according to the theoretical equation or three-dimensional model of the aspheric surface. The mirror surface is automatically measured to obtain the three-coordinate data of the actual point on the mirror surface, and finally obtained through data fitting processing. They are an important basis for determining the subsequent processing parameters and debugging of the optical system. This paper elaborates on the three-coordinate measurement method in terms of measurement principle, measurement plan formulation, measurement procedure, data processing and measurement uncertainty analysis. At present, it is mature and effective, and is widely used in engineering practice.