| This documentation is intended both for QC scientists and SciOps astronomers (who may want to ignore the technical information displayed in grey). | ||||||||||||||||||||||||||||
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| bottom plots | contact | ||||||||||||||||||||||||||||
| NAME | vimos_stdimg.py | |||||||||||||||||||||||||||
| VERSION |
1.0 -- February 2013 1.0.1 -- changes for qc_imadisp v1.5 (2014-01-20) 1.0.2 -- remove usage of has_key dictionary attribute (2014-03-12) 1.1 -- usage of qc_imaplt (2016-03-10) | |||||||||||||||||||||||||||
| SYNTAX | PYTHON | |||||||||||||||||||||||||||
| CALL |
processQC from $DFS_PRODUCT/STD_IMG/$DATE /home/vimos/python/vimos_astimg.py -i -a $AB | |||||||||||||||||||||||||||
| INSTRUMENT | VIMOS | |||||||||||||||||||||||||||
| RAWTYPE | IMG_ASTROMETRY | |||||||||||||||||||||||||||
| PURPOSE | QC checks for astrometric standard fields | |||||||||||||||||||||||||||
| PROCINPUT |
reduced astrometric field IMG_ASTROMETRY_REDUCED, table of found matches with catalogue IMG_ASTROMETRY_STAR_MATCH | |||||||||||||||||||||||||||
| QC1TABLE |
trending | table(s) in QC1 database: vimos_astrometry | |||||||||||||||||||||||||||
| TRENDPLOT |
trending | HealthCheck plot(s) associated to this procedure: trend_report_SKYCCD_XQ1_HC.html | trend_report_SKYCCD_XQ2_HC.html | trend_report_SKYCCD_XQ3_HC.html | trend_report_SKYCCD_XQ4_HC.html | trend_report_SKYCCD_YQ1_HC.html | trend_report_SKYCCD_YQ2_HC.html | trend_report_SKYCCD_YQ3_HC.html | trend_report_SKYCCD_YQ4_HC.html | |||||||||||||||||||||||||||
| QC1PAGE |
trending | associated documentation: astrometry_qc1.html | |||||||||||||||||||||||||||
| QC1PLOTS top |
astimg1.png reduced frame, identified stars are marked | |||||||||||||||||||||||||||
| QC1PARAM |
QC1 parameters calculated by the pipeline: QC1 DB names: -num_match | num_fit | sky_ccd_xrms | sky_ccd_yrms | sky_ccd_x_0_0 | sky_ccd_x_1_0 | sky_ccd_x_0_1 | sky_ccd_y_0_0 | sky_ccd_y_1_0 | sky_ccd_y_0_1 QC1 parameters calculated by the QC script: delta_xsky_xccd_512_610 | delta_xsky_xccd_1024_610 | delta_xsky_xccd_1536_610 | delta_xsky_xccd_512_1220 | ref_xsky_xccd_1024_1220 | delta_xsky_xccd_1536_1220 | delta_xsky_xccd_512_1830 | delta_xsky_xccd_1024_1830 | delta_xsky_xccd_1536_1830 | delta_ysky_yccd_512_610 | delta_ysky_yccd_1024_610 | delta_ysky_yccd_1536_610 | delta_ysky_yccd_512_1220 | ref_ysky_yccd_1024_1220 | delta_ysky_yccd_1536_1220 | delta_ysky_yccd_512_1830 | delta_ysky_yccd_1024_1830 | delta_ysky_yccd_1536_1830 | |||||||||||||||||||||||||||
| ALGORITHM |
Description of algorithms: num_match: number of stars matching with catalogue num_fit: number of stars actually used in astrometric solution sky_ccd_xrms: rms of astrometric solution for x sky_ccd_yrms: rms of astrometric solution for y sky_ccd_x_0_0, etc.: constant and linear coefficients of sky-to-CCD transformation matrix The CCD-to-sky transformation converts pixel coordinates onto a virtual plane which is free of instrument distortion. Coordinates of the virtual plane can be transformed into celestial coordinates using the WCS. The conversion matrix from CCD (X, Y) to virtual (Xvirt, Yvirt) coordinates is: Xvirt = Sum [a(i,j) X**i Y**j] Yvirt = Sum [b(i,j) X**i Y**j] with i, j from 0 to m, m is typically set to 3. The QC parameters sky_ccd_x_0_0, etc. measure the inverse transformation and include constant and linear coefficients only. For monitoring the astrometric quality, nine virtual data points (Xsky, Ysky) = (512, 610), (1024, 610), (1536, 610), (512, 1220), (1024, 1220), (1536, 1220), (512, 1830), (1024, 1830), (1536, 1830) are converted into CCD coordinates (Xccd, Yccd). The parameters ref_xsky_xccd_1024_1220 and ref_ysky_yccd_1024_1220 contain the difference between both, i.e. ref_xsky_xccd_1024_1220 = Xccd - Xsky for (Xsky, Ysky) = (1024, 1220). For the other parameters, this central difference has been subtracted, e.g. delta_xsky_xccd_512_610 = Xccd - Xsky - ref_xsky_xccd_1024_1220 for (Xsky, Ysky) = (512, 610). This allows to distinguish between the overall shift of the transformation (measured by ref_xsky_xccd_1024_1220, etc.) and changes in the distortion (measured by delta_xsky_xccd_512_610, etc.). | |||||||||||||||||||||||||||
| CERTIF |
Reasons for rejection: deviating coefficients or increased rms; underexposed or otherwise poor observation | |||||||||||||||||||||||||||
| COMMENTS | TBD | |||||||||||||||||||||||||||
| top | [2016-03-11T12:31:17] created by qcDocu v1.1.2, a tqs tool | |||||||||||||||||||||||||||
