SINFONI has four gratings, (see the User Manual for details concerning grating properties). Our QC1 checks using flat frames can be divided in several categories:

• PRODUCT QC PLOT. For each dark pipeline product and its associated raw frames we create a plot with the most significant features.
  
• DIFFERENCE FRAMES. A simple and efficient method to check short-term and long-term variations is to construct difference frames
  
• TRENDING This means that selected QC1 parameters are monitored as a function time. The purpose is to find long term variations which cannot detected on a single product frame.

A QC plot is generated for each pipeline flat product.

• Example SI_FLAT

• Most recent SI_FLAT [PS]

Figure caption

Upper Left: (columns) a) (blue) one single column at x=500 of the current product b) (magenta) one single column at x=500 of the reference product c) (red) median column collapsed over x=250-750 of the current product (= slit function) d) (green) median column collapsed over x=250-750 of the reference product (=slit function) (+0.05)	Upper Middle: (rows) a) (red) single row at y=500 of the current product. b) (blue) single row at y=600 of the current product c) (red as well) median row collapsed over y=250-750 of the current product. d) (green) median row collapsed over y=250-750 of the reference product (+0.05)	Upper Right: (histograms) of the current master flat, of the reference master flat and the difference of both histograms in logarithmic scale
Lower Left: (zooms) a) collapsed column of the current product b) (blue) single column at x=500 of the product c) (magenta) single column at x=500 of the reference.	Lower Middle : (differences) a) (red) current slit function divided by the reference slit function (enhances vertical shifts of the slit). b) (green) current lamp spectrum divided by the reference spectrum (enhances fringes)	Lower Right (Histograms) Histogram of the lamp-off frames (broad) and histogram of the lamp-on frames (narrow)

Inspection of arc product difference frames is a valuable way to check on the grating position.

• Current Product minus Reference Product shows long-term variations. The reference product is usually updated after an intervention or less frequently (diff).
• Current Product minus Last (Most Recent) Product shows the short term variations (ldiff)

Trending describes the variation of a QC1 parameter with time. Trending plots don't consist of control limits. Their purpose is more to document long term changes of QC1 parameters, which cannot be detected in process control charts. Trending plots can be subject of 'time series analysis'. The same QC1 parameters as the ones shown under the 'control chart' section are trended. More parameters are available via the interfaces of our QC1 parameter database.

• Lamp flux. The flux of the halogen lamp as measured by the detector depends on the lamp flux itself but also on the spectroscopic setting and the alignment of optical elements in the ray path. The lamp=off frame subtracted lamp=on fluxes as calculated by the recipe is monitored. Day-time spflat calibrations come in five pairs of lam=on/off frames. Night time calibrations (attached calibrations) come as one pair. The plots show HIERARCH ESO QC SPECFLAT NCNTSAVG. For each raw lamp-on frame the corresponding lamp-off frame is subtracted and the median is calculated. The QC parameter is the average of these 5 values.The lamp efficiency would be the lamp flux divided by DIT to get the count rate. Monitoring the lamp efficiency would make sense when monitoring in parallel the lamp amplifier value, an operationally defined value to get for the operational DIT for lamp flats the desired lamp flux.
  
  
  • FLAT_LEFF [PS]

• Bad Pixel, as derived from the NORM method of the sinfo_rec_mflat recipe
  
  
  • FLAT_BP [PS]

• Lamp-off flux, is used to monitor light/heat contamination in the optical path. The flux measured in lamp-off frames is usually a few counts above the reset anomaly of the same DIT (the dark counts), since a broad band filter is used for the lamp-off frames, wile the dark frames are taken with two excluding narrow band filters.The plots show HIERARCH ESO QC SPECFLAT OFFFLUX, that is the average of the (five) off-lamp medians.
  
  
  • FLAT_OFF [PS]

• Fixed Pattern noise, in as selected region on the array. This is a simple standard deviation of the flat product frame. The region is specified in the sinfo_rec_mflat.rc file. In P75 it was the central quarter [@512,@512:@1536,@1536]
  
  
  • FLAT_FPN-1 [PS]

• Fixed Pattern noise, in as selected region (another region than region 1) on the array. This is a simple standard deviation of the flat product frame. The region (region 2) is specified in the sinfo_rec_mflat.rc file. In P75 it was a area on one single slitlet [@1350,@1000:@1390,@1200]
  
  
  • FLAT_FPN-2 [PS]
    
    
• Vignetting in slitlet #1 and #32:
  slitlet #1 and slitlet #32 corresponding to the uppermost and lowermost slitlet in the FOV, and are projected onto the central part of the detector and are subject of vignetting, meaning the countrate can be a few 10% lower than in the other slitlets. The light loss is dependent on the grating and the pre-optics. We monitor the relative countrate (e.g. median counts in slitlet #1 devided by median count rate of the whole frame that should be 1 ) in a selected window of slitlets #1 and slitlet #32 in the master flat frame.
  
  
  • FLAT_RF1 [PS]
    
  • FLAT_RF32 [PS]