Analysis of phase retrieval in active imaging

This report describes a collection of research tasks which develop techniques to reconstruct fine-resolution images of satellites coherently illuminated by lasers. Two major imaging modes were developed. In the first, called imaging correlography, an incoherent image of the coherently illuminating target is reconstructed from multiple realizations of the intensity of the nonimaged (aperature-plane) laser speckle pattern backscattered from the target. In the second mode, a coherent image of the target is reconstructed from a single realization of the nonimaged laser speckle pattern. In the latter mode, reconstruction methods were developed for the case which contains a strong glint (or glints) and for the case in which one has partial information about the phase of the optical field backscattered by the target.