In the decade since its invention by Labeyrie in 1970, speckle interferometric techniques have evolved from simple optical processing of photographic images to high-speed digital processing of quantum-limited video data. This progress has been summarized in preceeding papers by McAlister and Weigelt in this colloquium.
The basic hardware of our system has been described in Hubbard, et al. (1979 – The basic speckle camera) and in Hege et al. (1980 – The intensified video system). These capabilities have been successfully applied to observations over a dynamic range of 16 magnitudes, from Betelgeuse (Goldberg, et al. 1982) and Capella (this paper), at one extreme, to Pluto/Charon (Hege, et al. 1981a) and the 16th magnitude resolved QSO system PG1115+080 (Hege, et al. 1981b) at the other. To accomodate this dynamic range two distinct data-recording/data-processing modes have been implemented. The Analoue mode records the image intensity for each pixel in the speckle interferogram. This is applicable for objects brighter than 7th to 10th magnitude, depending upon telescope aperture, observing band-pass and detector image scale. For fainter objects the Event mode records individual photoelectron addresses in the speckle interferogram.