| | 8 | I found errors with the reference database that I generated: it turned out that relphot failed to set the mean mags based on the synthetic photometry, if no good PS1 photometry existed. This left large gaping holes in some places. I needed to modify relphot and re-run it, and then re-extract the reference database subset. I added code to psastro to apply JT's w-r vs g-r color trend to the data, so that w-band images can be well calibrated using this new database. Looking at the astrometric and photometric residuals across the sky: astrometry looks very solid. photometry looks good in general, but there are a number of exposures which were rejected from the analysis, and have not been adjusted to match the rest of the system. I'll need to run a clean up stage to make them consistent, but for now I think the reference database is good (because the mean magnitudes exclude those rejected exposures). We are going to re-run SAS over the weekend with the new reference database. |
