Restoration of astigmatism and curvature of field*

Abstract

With a linear, incoherent system model, the point-spread functions that describe imaging in the presence of astigmatism and curvature of field are space variant. These functions are derived and coordinate transformations are used to reduce significantly the dimensionality. For astigmatism, the general four-variable problem reduces to a family of identical two-dimensional space-variant problems. With both aberrations present, an additional space-invariant transform operation is required. Singular-value-decomposition techniques analogous to inverse Fourier filtering are used for pseudo-inverse solutions of the simplified equations.