Chandra X-Ray Observatory
	(CXC)
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Last modified: 13 March 2017

PCAD: Pointing Control and Aspect Determination


Determines the Chandra aspect solution, i.e. the position pointed to by the Chandra X-ray mirror (HRMA) optical axis. The PCAD has a system of gyroscopes to monitor short-term changes, and a 4.25 inch diameter optical telescope with a CCD imager (for longer term corrections and tying to an astrometric reference frame).

See the Proposers' Observatory Guide (POG) for technical details.



Last modified: 13 March 2017
Smithsonian Institute Smithsonian Institute

The Chandra X-Ray Center (CXC) is operated for NASA by the Smithsonian Astrophysical Observatory. 60 Garden Street, Cambridge, MA 02138 USA.   Email:   cxchelp@head.cfa.harvard.edu Smithsonian Institution, Copyright © 1998-2017. All rights reserved.