| 8 | | I used the newly generated MD04 astrometry and photometry reference database to re-process all of the MD04 data taken since Fall 2009. I selected a 'good' sample of images (good photometric conditions and good seeing) and made an initial deep stack in all filters. The write-up on this analysis is available [wiki:PS1_MD04_RefStack on the wiki as PS1_MD04_RefStack]. With the internal reference photometry and astrometry database, we get much more consistent zero points from the on-the-fly analysis and much better astrometry: the astrometry seems to be in the range of 15mas, consistent with other tests. The photometry is less clear because we need to check for the correct airmass extinction terms. Zero points seem to be cluster within about 1% of the nominal zero points, but there are some outliers which we need to understand (the bright outliers are more surprising than the faint outliers). There is also a problem with the exposure time map produced by the stacking since these deep stacks over run the dynamic range of the output files as defined for the standard processing. I made this set available to the consortium, but I'll be doing some more re-processing of this data, including a version with 0.258 arcsec static sky pixels. |
| | 8 | I used the newly generated MD04 astrometry and photometry reference database to re-process all of the MD04 data taken since Fall 2009. I selected a 'good' sample of images (good photometric conditions and good seeing) and made an initial deep stack in all filters. The write-up on this analysis is available [wiki:PS1_MD04_RefStack on the wiki as PS1_MD04_RefStack]. With the internal reference photometry and astrometry database, we get much more consistent zero points from the on-the-fly analysis and much better astrometry: the astrometry seems to be in the range of 15mas, consistent with other tests. The photometry is less clear because we need to check for the correct airmass extinction terms. Zero points seem to be cluster within about 1% of the nominal zero points, but there are some outliers which we need to understand (the bright outliers are more surprising than the faint outliers). There is also a problem with the exposure time map produced by the stacking since these deep stacks over run the dynamic range of the output files as defined for the standard processing. I made this set available to the consortium, but I'll be doing some more re-processing of this data, including a version with 0.258 arcsec static sky pixels. |
