Psf calibration in astronomical imaging - physical constraints for a noisy problem

Physically constrained iterative deconvolution attempts to realize the solution of an ill-posed problem, the iterative estimation of both the object function and the corresponding set of image point- spread-functions given a set of noisy realizations of images obtained with less than perfect optical imaging systems. Conjugate gradient-driven iterative estimation is used with physical constraints to guide the result to a physically consistent solution. The Art of using physically constrained iterative deconvolution in astronomical imaging, with and without adaptive optics, is discussed.