Method for determining asphericity gradient of circular aperture quadric surface

The invention discloses a method for determining the asphericity gradient of a circular aperture quadric surface based on the third-order aberration theory. A full-aperture quadric surface can be regarded as a circular aperture quadric surface with an inner ring aperture of 0. The method for determining the asphericity gradient of the circular aperture quadric surface overcomes the shortcomings that the asphericity gradient calculation of the full-aperture and circular aperture quadric surfaces has no function form and uniform expression, and is unintuitive; the theory is reliable, and the result is simple. The expression of the asphericity gradient of quadric surfaces with various apertures can be quickly, accurately and directly written by using the aspheric parameters; the application range is wide; the work efficiency can be significantly improved; and the method for determining the asphericity gradient of the circular aperture quadric surface provides a basis for formulation of processing and testing sch