Hi John, Thanks for your messages.
davis@space.mit.edu said:
> Until the PSF fraction library becomes available
I'm delighted to learn that the CXC is working on the problem of tabulating
the PSF fraction as a function of extraction radius and off-axis angle.
Such issues -- specifically choosing the optimal extraction radius as a
function of source brightness, background, and off-axis angle, then computing
the corresponding PSF fraction -- are currently causing much angst here at
PSU, particularly since some observations have ~1000 point sources to extract.
{Of course the optimal extraction region is a non-circular shape off-axis, but
we're a long way from being able to worry about that one in automated
processing.}
If the CXC currently has any PSF fraction results off-axis we'd be delighted
to obtain them. Or, we'd be delighted to obtain any tools you may have for
generating such results, perhaps a script for generating a PSF at a specified
(X,Y), running wavedetect to find the PSF's "position", then computing
encircled fraction for a specified radius about that position.
Regards,
Pat
-- ==================================================================== Patrick S. Broos, Systems Analyst/Programmer patb@astro.psu.eduDepartment of Astronomy and Astrophysics My office 814-863-7947 Penn State University 525 Davey Lab FAX 814-863-8686 University Park, PA 16802-6305 http://www.astro.psu.edu Group office 863-9550 ====================================================================
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