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Pointing Performance


The AMCS is specified to a pointing accuracy of 1', i.e., with `` tex2html_wrap_inline1852 '' confidence the distance between the actual pointing direction and the requested position will be less than 1'.

The pointing stability, i.e., the movement of the optical axis of the XRT while on target, is less than 5'' per second, with a jitter radius of tex2html_wrap_inline1858 .

PSPC observations will be carried out in a special ``wobble'' mode (for details see § 4.2.2; gif and 10.6gif) which slowly moves the telescope's pointing direction back and forth ( tex2html_wrap_inline1860 in 400 seconds of time) in order to prevent unwanted shadowing of X-ray sources behind opaque structures in the PSPC. A similar ``wobble'' is performed for the HRI ( tex2html_wrap_inline1862 in 400 seconds of time).

The ROSAT attitude determination is done post facto on ground by the German Space Operations Center (GSOC) to a specified accuracy of 6''.

Michael Arida
Tue Jun 11 16:18:41 EDT 1996