Image correlation in a coded mask X-ray telescope.

A description of the analytical procedures developed for the analysis of flight data from a coded mask X-ray telescope is presented, with emphasis on aspects particularly relevant to the data processing. The procedures involve the binning of the photons into detector plane images in various time and energy ranges, the reconstruction of these to form sky images using a Hadamard Transform to perform a cyclic cross-correlation with the mask pattern, and, where necessary, the coadding of sky images obtained in different time intervals. Various necessary corrections and precautions (energy corrections, photon position corrections, detector plane image corrections, and background nonuniformity corrections) are discussed.