7 March 2003 ASTROCAM: offner re-imaging 1024 X 1024 InSb camera for near-infrared astrometry on the USNO 1.55-m telescope
Author Affiliations +
Abstract
In order to extend the US Naval Observatory (USNO) small-angle astrometric capabilities to near infrared wavelengths we have designed and manufactured a 1024 x 1024 InSb re-imaging infrared camera equipped with an array selected from the InSb ALADDIN (Advanced Large Area Detector Development in InSb) development program and broadband and narrowband 0.8 - 3.8 μm filters. Since the USNO 1.55-m telescope is optimized for observations at visible wavelengths with an oversized secondary mirror and sky baffles, the straylight rejection capabilities of the ASTROCAM Lyot stop and baffles are of critical importance for its sensitivity and flat- fielding capabilities. An Offner relay was chosen for the heart of the system and was manufactured from the same melt of aluminum alloy to ensure homologous contraction from room temperature to 77 K. A blackened cone was installed behind the undersized hole (the Lyot stop) in the Offner secondary. With low distortion, a well-sampled point spread function, and a large field of view, the system is well suited for astrometry. It is telecentric, so any defocus will not result in a change of image scale. The DSP-based electronics allow readout of the entire array with double-correlated sampling in 0.19 seconds, but shorter readout is possible with single sampling or by reading out only small numbers of subarrays. In this paper we report on the optical, mechanical, and electronic design of the system and present images and results on the sensitivity and astrometric stability obtained with the system, now operating routinely at the 1.55-m telescope with a science-grade ALADDIN array.
© (2003) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jacqueline Fischer, Jacqueline Fischer, Frederick J. Vrba, Frederick J. Vrba, Douglas W. Toomey, Douglas W. Toomey, Bob L. Lucke, Bob L. Lucke, Shu-i Wang, Shu-i Wang, Arne A. Henden, Arne A. Henden, Joseph L. Robichaud, Joseph L. Robichaud, Peter M. Onaka, Peter M. Onaka, Brian Hicks, Brian Hicks, Frederick H. Harris, Frederick H. Harris, Werner E. Stahlberger, Werner E. Stahlberger, Kris E. Kosakowski, Kris E. Kosakowski, Charles C. Dudley, Charles C. Dudley, Kenneth J. Johnston, Kenneth J. Johnston, "ASTROCAM: offner re-imaging 1024 X 1024 InSb camera for near-infrared astrometry on the USNO 1.55-m telescope", Proc. SPIE 4841, Instrument Design and Performance for Optical/Infrared Ground-based Telescopes, (7 March 2003); doi: 10.1117/12.461033; https://doi.org/10.1117/12.461033
PROCEEDINGS
14 PAGES


SHARE
RELATED CONTENT

XUV Wide Field Camera for ROSAT
Proceedings of SPIE (July 27 1989)
Performance of HAWK I the new high acuity wide...
Proceedings of SPIE (July 08 2008)
FORCAST a facility 5 to 40 um camera...
Proceedings of SPIE (June 19 2000)
NASA IRTF tip-tilt secondary system
Proceedings of SPIE (September 17 1997)
MANIAC a new mid and near infrared array...
Proceedings of SPIE (October 22 1997)
FORCAST: the facility mid-IR camera for SOFIA
Proceedings of SPIE (June 27 2006)

Back to Top