Minimum error image reconstruction for coded mask telescopes

School of Physics and Space Research, The University of Birmingham, Birmingham, B15 2TT, UK

Send offprint request to: G.K. Skinner

Received: 11 March 1996
Accepted: 2 May 1996

Abstract

A new method is proposed for reconstructing the data from coded aperture X/γ-ray telescopes. This technique, based on the Wiener criterion, is essentially a generalisation of existing Wiener filtering methods but is not confined to systems with position independent point source response functions. The reconstruction method trades off the image degrading effects of statistical detector noise with the effects of imperfect source field coding, to produce a minimum error source field estimate. It offers advantages if the coding properties of the mask-detector configuration considered are not `ideal' and is particularly useful where multiple dithered observations are made of a given source field. The proposed method is applied to simulated data and to data from a recent balloon flight of an experimental coded mask telescope. It is shown to give better quality images than those formed by more conventional methods.