Accuracy transfer method of large aperture standard mirrors’ absolute surface error

An accuracy transfer method of the standard flats absolute surface error is proposed. When we acquire the absolute surface error of a standard flat, we can use this method to transfer its accuracy to another standard flat. According to the experimental results, we conclude that Zernike polynomials power term can fit the changing amount very well. In order to deal with the surface difference at different temperatures, we propose a method using the lines absolute surface data extracted by classical three-flat test to estimate the power amount. A well manufacturing optical part is tested by two interferometers. The use of this method can lessen the difference between the results of two-dimensional distribution.