Thick Aberrator Compensation Using Phase Diversity

The study of a method of imaging through thick turbulent layers using extended sources is proposed. The method uses the technique of phase diversity to generate multiple images of the source in multiple focal planes. A parametric description of the turbulent distortion and the source is found by a multidimensional fit of the data to a model of the turbulent distortion and the extended source. The phase diversity method simultaneously solves for the phase distortion (as a function of look angle) and the source distribution. In addition to the estimate of the source, the informatin can be fed back into an adaptive optics control system. The phase distortion can be parameterized in the pupil plane as a function of look angle or in a layered model where the layers sit at different distances from the pupil. Either model lends itself to estimation of the correcting phase to be applied at each element of a multi-conjugate adaptive optics system that corrects for anisoplanatic distortion. This method has application to imaging systems with synthetic beacons and passive systems that only use ambient light.