Recovery of Intensity Information from Speckle Data

The achievements of speckle interferometry in recovering diffraction limited spatial information, primarily by optical processing of photographic data, have been well summarized by McAlister in a preceeding paper. In general, the recovery of intensity information has received less attention mainly because of complications such as the need for accurate deconvolutions and noise bias corrections. Methods for producing image power spectra (or the equivalent image autocorrelation functions) from digitally recorded speckle interferograms, as well as methods for correcting these functions for seeing effects, are described in our previous paper, Cocke, et al . in this colloquium. In this paper we discuss effects of instrumental response and photon statistics, the so-called noise bias, and procedures for correcting these effects in order to recover binary star relative intensity information from speckle interferometric data. We find for Capella δm v = 0.48.