Research on the High-resolution Imaging of Astronomical Objects Based on the Phase Difference Method

High resolution imaging of astronomical objects based on the phase difference method consists in estimating the object and the wave front phase distribution introduced by atmospheric turbulence from one or more pairs of shortexposure images collected simultaneously in focus and out of focus. On the basis of computer simulations of the telescopic imaging system and the image acquisition process of the phase difference method, we used the signal estimates and the optimization theory to determine the objective function under a Gaussian noise model, and carried out numerical solution of the image restoration problem with the finite inner memory quasi-Newtonian method suitable for large scale unconstrained optimization. The restored results show that the present technique based on the phase difference method can effectively eliminate the influence of atmospheric turbulence and solve the problem of restoring extended astronomical objects.