Technique for obtaining visibility amplitudes from atmospherically disturbed interferograms

We describe the general data-reduction techniques that we developed to deal with stellar interferograms. The techniques that we describe here were used to obtain the fundamental visibility data from raw Earth-scanned interferograms obtained with the infrared Michelson array stellar interferometer. The reduced visibility data have resulted in new direct angular diameter measurements and effective temperature determinations for α Her, α Ori, and Mira. These astrophysical results were previously published. We point out that the data-reduction techniques described here are completely general in the sense that they can be used to reduce the data from any stellar interferometer that records the temporal data stream as the fringe packet is swept by the detectors.