In some optical systems in which a large field of view (and hence a large detector) is required, it is the detector which drives the total system cost. We propose a concept, and demonstrate an optical system, for an astronomical multiplexer. The instrument projects different portions of the telescope focal plane into a single (possibly) small detector without changing the original plate scale of the image. The resulting image is a superposition of the different portions of the field of view. Since in most cases astronomical images are sparse, photometric measurements can be done directly on the combined images for most objects in the field. We discuss an outline of the concept of multiplexing, in terms of its signal-to-noise properties, and multiplexed image reconstruction algorithm. Furthermore, we present an optical design for an astronomical multiplexer we recently constructed along with some first light images.

Date Published: 28 July 2014
PDF: 7 pages
Proc. SPIE 9147, Ground-based and Airborne Instrumentation for Astronomy V, 91475U (28 July 2014); doi: 10.1117/12.2055421

Published in SPIE Proceedings Vol. 9147:
Ground-based and Airborne Instrumentation for Astronomy V
Suzanne K. Ramsay; Ian S. McLean; Hideki Takami, Editor(s)