On the influence of scanning speed in turbulence degraded one-dimensional stellar images

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Abstract
When observing an unresolved star, a mask consisting of a linear array non-redundantly spaced apertures placed in front of the telescopic pupil gives rise to an image composed of discrete superimposed fringe patterns within an Airy disc envelope. Due to atmospheric turbulence the incident luminous wavefronts are subject to phase perturbations given rise to rapid and independent random movements of each fringe system. When analyzed by a scanning slit the image autocorrelation and corresponding spectrum exhibit a deterioration related to the scanning speed and to the characteristic evolution time of the turbulence. Theoretical expressions are developed for this dependence and are shown to be in good agreement with experimental results obtained by laboratory simulation. An optimal scanning speed can be determined for a given set of turbulence, telescope aperture and noise characteristics.