RA / Dec mapping did change centroid locations, but not really for the better. A deeper analysis is probably necessary, but nevertheless I'm not convinced mapping type is the problem. The list of possible answers to the question of why my pointing models don't match Meredith's:
- The new mapping is shifting the centroid
- The centroiding method I'm using is different / incorrect
- There is still something in the pointing we haven't caught
The lack of systematics suggests that the third option is not correct. The first seems the most likely, but also the most difficult to track down. I don't know where to go with #2. I've updated the code so that the pointing model correction offsets in RA/Dec are written to the FITS header. This will be the standard in all future runs for individual observations. The calculation of this offset post-mapping is straightforward but it's nice to have a redundant error check. The report for Monday will be kind of empty, sadly. However, I think I can say that I'll now move on to testing the previous problems we faced, in particular that we could not match the pointing across whole fields (L111). If THAT is fixed, then at least we know that whatever my pipeline is doing differently (e.g. PA at all times...) is useful if not 100% correct. I'll need to be in the office to test the field mappings, though, because ds9 display doesn't work well over wireless. I'll do a remote run of the individual L111 and W5 maps to compare to previous ones.