Experiments on speckle imaging using projection methods

In this paper we present some experimental results of speckle imaging for near-diffraction-limited observation of ground-based scenery and astronomical objects through atmospheric turbulence. The method of alternating projections onto convex sets is used for iterative reconstruction of the point-spread function (PSF), combined with Wiener filtering for deconvolution and several pre-processing techniques. A modification of the optical system with aperture segmentation is considered. The results of imaging on a horizontal path and astronomical imaging are reported and compared with time averaged and best frame images. Apparent image improvement is demonstrated in a field much wider than the isoplanatic patch size.

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