USE OF A REFERENCE SOURCE IN PROBABILITY IMAGING

We describe the relations between the statistics of the speckled image I(x) that is produced by an astronomical object at the focus of a telescope and the statistics of the point-source speckle pattern S(x) that is obtained under comparable conditions of turbulence. We show that the characteristic function (CF) of I(x) can be written as a central slice of a higher-order CF of S(x); as a consequence, probability density functions (PDF's) of I(x) and S(x) are related to one another by means of projections. An illustration, consisting of one-dimensional scans obtained with the European Southern Observatory's slit-scanning infrared specklograph, is made for real data. It is shown how the onefold and twofold PDF's of a double star can be synthesized from the twofold and the threefold PDF's of the reference source.