Interferometric technique for recording and restoring images degraded by unknown aberrations*

A method for recording and restoring images that have been degraded by unknown aberrations is described. Several images are recorded with different masks placed in the pupil of the optical system. If these images are Fourier analyzed and certain phases are combined algebraically in the proper manner, the effects of the unknown aberrations can be removed, with an uncertainty concerning the absolute location of the object with respect to the imaging system. Experimental results are reported. The sensitivity of the method is analyzed, and the applicability of the technique in astronomical imaging is considered. The method shows considerable promise for high-resolution imaging of fine-grain structure on the solar surface.