https://pfspipe.ipmu.jp/jira This file is an XML representation of an issue en-us 8.3.4 803005 13-09-2019 https://pfspipe.ipmu.jp/jira/browse/INSTRM-1892 Instrument control development <p>In order to convert measured flux on AG CCDs to real unit (<a href="https://pfspipe.ipmu.jp/jira/browse/INSTRM-1515" title="Convert measured fluxes to absolute units" class="issue-link" data-issue-key="INSTRM-1515"><del>INSTRM-1515</del></a>), study the relation between measured flux vs Gaia magnitude using the existing data. (Note: the additional window has been installed since November 2022). Dependency in Zenith angle, zero points etc will be studied.</p> <p>Per requested, the visit list of field acquisition, for which we took AG took data at its on-focus position. is attached (visit_AGonFocus_202211.txt).</p> INSTRM-1892

Study flux vs Gaia magnitude using the November 2022 data

Task Normal Done Done karr yuki.moritani EngRun Sun, 12 Mar 2023 20:33:03 +0000 Thu, 18 May 2023 08:03:02 +0000 Thu, 18 May 2023 06:12:16 +0000 0 2 <p>We can extract a general conversion factor from detected photons to GAIA magnitudes, however, the variation in photometric quality is large enough to obscure any relation based on zenith angle; for that, we would need photometric conditions. </p> <p>I've processed the AG data we have which is both focussed, and had a good enough transformation to produce a match with the Gaia catalogue. For each frame, I fit a linear function with outlier rejection to the brighter sources between log10(flux) and Gaia g band magnitude, where the flux is the instrumental flux returned by sextractor.  </p> <p>We don't see any systematic variation in the conversion based on the camera ID, the side of the detector (glass vs no glass), or the altitude of the observations.  The variation in photometric quality overwhelms any of these factors. </p> <p>The first plot shows an example of a single fit; the colour coding is by altitude, and the line shows the fit/fitted region. </p> <p>The second plot shows all the individual fits (one fit per exposure ID) on a single plot. From this plot, I selected the median slope as an approximate fit to the Gaia magnitudes. </p> <p> </p> <p>Code is updated and pushed to branch for testing. The coefficients of the fit are stored in the agcc.yaml file; the updated version is in the corresponding branch of pfs_instdata. Database write has not been added yet, as this will require a schema update. </p> <p>The conversion formula was implemented for the 2023 April/May run. Analysis of the new data will be done under the new ticket (<a href="https://pfspipe.ipmu.jp/jira/browse/INSTRM-1979" title="Calculate flux conversion for AG camera with April Data" class="issue-link" data-issue-key="INSTRM-1979"><del>INSTRM-1979</del></a>).</p> Development Rank 0|zzswdg:hs Sprint PreEng11Apr1