Curvature radius measuring method based on correlation coefficient matching

The invention discloses a curvature radius measuring method based on correlation coefficient matching. The curvature radius measuring method comprises the following steps: (1) preprocessing an interference pattern; (2) solving an initial curvature radius; and (3) correlation coefficient solving: taking R belongs to {R +/-delta R} as an index range, simulating a Newton ring interferogram IR (x, y) corresponding to each curvature radius R in the index range, respectively calculating correlation coefficients of IR (x, y) and I1 (x, y), and finding out the curvature radius R corresponding to the maximum value of the correlation coefficient, namely the curvature radius of the spherical mirror to be measured. According to the method, a single Newton ring interferogram is adopted, the initial curvature radius is obtained according to the radius of the dark ring, the index range is set according to the initial curvature radius, then the high-precision curvature radius to be measured is obtained through correlation co