Image truncation in stellar speckle imaging

Abstract

Stellar speckle images are often truncated by the edges of the image detector. It is shown that even modest amounts of image truncation can cause important errors in the second-order spectra of speckle interferometry and the Knox–Thompson algorithm. A method is presented for estimating an approximate upper bound on the truncation error given the telescope, atmospheric seeing, detector size, and spatial sampling rate. Reconstructed images of the triple star ADS 11344 from simulations and from real data illustrate the distortions and negative artifacts caused by image truncations.