XMM-Newton Science Analysis System
ommosaic (ommosaic-2.11) [xmmsas_20211130_0941-20.0.0]
- Whilst tests have so far shown that scattered-light features
do not effect the cross-correlation algorithm, further testing is
underway and the method should be used with caution.
- Tests using the cross-algorithm on aspect-corrected sky-images have
so-far shown the computed offsets to be small (less than 0.2 pixels). If both the
aspect-correction and the cross-correlation algorithm were perfect, they should be zero. However the error in the
aspect-correction can be up to 1 arc sec, and further testing needs to be done to evaluate any differences.
- It would be desireable to perform a further aspect correction on the sky-images-
this would require either a new OM task or, possibly, a modification to omsrclistcomb. Note that
even if the sky-images have not been aspect-corrected, the coordinates of the sources in the observation source-list
file may have.
XMM-Newton SOC -- 2021-11-30