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NACO Quality Control:
ZERO POINT frames

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zeropoints
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QC1 database (advanced users): browse | plot
   Click on CURRENT to see the current trending (Health Check).
   Click on HISTORY to see the historical evolution of the trending.


The ZERO POINT frames (imaging standard stars) are obtained during the night time NACO operation for different instrumental setups. Each ZERO POINT consists of 5 raw frames. Dedicated pipeline recipe "naco_img_zpoint" builds 8 difference frames from those 5 input frames, rejects the minimum and maximum, and takes median of the remaining 6 zero points values. The subtraction pattern is: #1-#2, #2-#1, #2-#3, #3-#2, #3-#4, #4-3, #4-#5, #5-#4.

The conversion formula from ADUs to magnitudes is:

zmag = mag + 2.5 log10(flux/DIT)

where "zmag" is the computed zero point, "mag" is the known magnitude of the standard star in the observed band, "flux" is the flux measured in ADUs in the image and "DIT" is the detector integration time.

Note that the zero points do not include extinction nor the color correction.

This is an example of a pipeline product of the "naco_img_zpoint" recipe.


top zeropoints

QC1 parameters

parameter QC1 database: table, name procedure
"zpoint" naco_zp, zpoint zero point determined by the pipeline recipe naco_img_zpoint
"zpoint_rms" naco_zp, zpoint_rms RMS of the photometric zero point
"flux_counts" naco_zp, flux_counts mean flux in counts

The following health check plot shows the temporal evolution of the NACO photometric zero points (not corrected for extinction). Only the observations with broad filters Ks, J, H are selected.
top strehl

QC1 parameters

parameter QC1 database: table, name procedure
"strehl" naco_zp, strehl mean Strehl ratio determined by the pipeline
"strehl_rms" naco_zp, strehl_rms RMS of the Strehl ratio
"strehl_error" naco_zp, strehl_error error of the Strehl ratio

The health check plot shows the Strehl ratio calculated for the imaging standard star observations in filters Ks, J and H.

History:

Up to 2015-06 HC plots for zeropoints and peak counts contain data for camera S27

From 2015-06 on these plots contain data for S13, since the camera wheel was stuck from 2015-06 until 2015-12.

In 2015 the upper right detector quadrant (only this quadrant) shows a defect: every 8th column is dead (no response).

From 2015-06 on for the S13 camera:
As a consequence, the photometric standard star raw frame, which shows the star in the upper right quadrant is excluded when calculating the photometric zeropoint.
Meaning one (frame #2) of five raw frames generated by the template is ignored.

From 2015-12 on the lower left detector quadrant (only this quadrant) shows the 8th column effect.
As a consequence, the photometric standard star raw frame, which shows the star in the lower left quadrant is excluded when calculating the photometric zeropoint.
Meaning one (frame #4) of five raw frames generated by the template is ignored.


 
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