The EM Algorithm for Imaging with Gaps in the Detector Plane
Abstract
γ-ray telescopes based on coded-mask techniques does not give a direct image of the sky sources but its correlation with the mask response function. To obtain an image of the sky sources one has to treat mathematically the detected image, usually by correlating it with a reconstruction array (correlation methods). Unfortunately this kind of methods, although quite fast, have some limitations in the reconstructed image and in handling the real telescope response. To improve these results, several reconstruction methods have been developed and used. In the case of LEGRI (a γ-ray coded-mask telescope developed for the University of Valencia) we have used the EM algorithm, an iterative maximum likelihood algorithm with very good response and with good handling of the telescope response.
- Publication:
-
Astrophysics and Space Science
- Pub Date:
- March 2001
- Bibcode:
- 2001Ap&SS.276..291B