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Information On DQC Plots And Log

This document describes the QC and log information available on the Vista Progress report page.

Summary Plots

The two plots on the summary1.gif files use different colour codes for each filter:

  • J : blue
  • H : green
  • K : red
  • Y : black
  • Z : cyan
  • NB118: purple

The plots on the summary2.gif files use different colour codes for each chip:

  • Chip #1 : red
  • Chip #2 : green
  • Chip #3 : blue
  • Chip #4 : cyan
  • ......................

On each plot, there is one dot per data product (catalogue). The 5-sigma magnitude limits are computed for the output product frames for each OB. Zeros for the seeing indicate no measure was possible and usually indicate a problem with the data for that detector.


Columns:- note the 18 entries, one for each detector or tile in running order 1-18 for each catalogue file summarised

  1. Run no.           - filename using CASU naming convention
  2. Ext                    -  extension number or "tl" if from tile catalogue
  3. Object Name  - value from OBJECT keyword
  4. RA                    - recorded telescope Right Ascension
  5. Dec                  - recorded telescope Declination
  6. Equinox          - value of EQUINOX keyword
  7. AM                   - average of start and finish airmass
  8. Date  UT         - as it says
  9. Exp                  - value of EXP_TIME (s) from header, this is equivalent to DIT
  10. Filt                   - filter name
  11. Seeing            - average of FWHM (arcsec) for stellar sources on detector
  12. Sky                  - estimate of sky background per pixel (ADU)
  13. Noise              - estimate of sky rms noise per pixel (ADU)
  14. Ellipt                - average ellipticity of stellar sources on detector
  15. APcor              - aperture correction for default "core" size (default 3 pixels radius, 2.0 arcsec diameter)
  16. STDrms          - rms error (arcsec) in astrometric solution
  17. MagLim          - estimate of 5-sigma limiting magnitude for stellar sources
  18. Totexp             - product of DIT*NDIT*NJITTER  (x2 if standard tile) i.e. total exposure time for majority of pixels

Photometry Plots

The colour codes used in the plots shown in the photom.gif are used to show the different filters and use the same convention described above for page 1 summary plots.
The points are the instrumental zero-points derived from 2MASS cross-matches (+colour equations) using for now a nominal extinction value of 0.05 in all bands. The dashed lines gives a rough reference of the expected photometric zero point for a perfectly photometric night. The open dots on the rightmost part of the plot show for each filter the mean zero point and the corresponding error bar (variation) for the whole night.
The open circles in the data points are ones where the measured seeing is worse than 2 arcsec or the stellar ellipticity is worse than 0.3, i.e. the images are severely trailed.

Observation log

The index files with the observation log for each night contain the following information:

  1. image name
  2. value of the PROJECT header keyword (Time-allocation code).
  3. TPA in degrees
  4. TPD in degrees
  5. value of the OBJECT keyword (Object name from telescope).
  6. value of the FILTER keyword (Filter name).
  7. value of the DIT keyword (Integration time per exposure [s]).
  8. value of the DATE-OBS keyword (Date time (UTC) of start of observation).
  9. value of the NDIT keyword (Numbers of coadds in the exposure)
  10. value of the NJITTER keyword (Number of positions in telescope jitter pattern).
  11. value of the JITTER_I keyword (Serial number in this telescope jittern pattern).
  12. value of the DET NCORRS keyword (Name of the camera readout mode).

13.  value of the JITTER_X keyword (Offset in x [arcsec])
14.  value of the JITTER_Y keyword (Offset in y [arcsec])