GCN Circular 5872
Subject
Swift XRT on-board boresight update
Date
2006-11-27T16:43:13Z (20 years ago)
From
Jamie A. Kennea at PSU/Swift-XRT <kennea@astro.psu.edu>
J. A. Kennea, D. N. Burrows (PSU), A. Moretti (INAF-OAB), M. Perri (ASDC),
M. Capalbi (ASDC), L. Angelini (NASA/GSFC) and J. E. Hill (USRA) report on
behalf of the XRT instrument team:
As previously reported there has been a change in the XRT boresight since
about 1 May 2006 that resulted in decreased positional accuracy (Burrows
et al., GCN Circ. 5628, GCN Circ. 5750). On November 24th, 2006 the XRT
team updated the onboard boresight definition used to calculate automatic
burst positions to correct for this change. As a result of this update the
on-board calculated position and position error reported in the XRT
Position Notices are now correct. We note that this change does not
correct positions derived from ground processed data, which will require
an update to the CALDB TELDEF file. This is due to be released to the
community with the next Swift software update. Note that the XRT Team are
currently utilizing a pre-release of this new TELDEF file when reporting
positions in GCN Notices and Reports.