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MIDI Quality Control:
KAPPA Matrix (transfer ratio)

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Kappa Matrix (transfer Ratio)
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top Kappa Matrix

In the SCI_PHOT mode, we observed simulatneously the photometric and the interferometric channels. The beam splitter send some of the light in the photometric channels and the reminder is sent to the Interferometric channel.

The kappa matrix (or transfer ratio) defines the relationship between the intensity in the interferometric channels and in the photometric channels. It depends on the splitting ratio
  • I1=K11*PA + K12*PB, with I1 the interferometric channel 1, PA the photometric beam from beam A
  • I2=K21*PA + K22*PB, with I2 the interferometric channel 1, PB the photometric beam from beam B

The kappa matrix is measured at least once a night when there are SCI_PHOT observations. It consists of photometric observations (several frames (typically 3000 to 5000) are taken with beam A open, then the same amount of frames are taken with B open.

  • When Beam A is open PB=0 K11=I1/PA and K21=I2/PA
  • When Beam B is open PA=0 K12=I1/PB and K22=I2/PB

Data Input and pipeline steps

The input files are PHOTOMETRY files taken with AOPEN and BOPEN in the SCI_PHOT mode. The pipeline analysed the different channels and calculates the kappa matrix coefficients

QC1 parameters

The QC1 parameters can be found in the QC1 database midi_kappa. The median and the standard deviation of each kappa coefficient is ingested and trended. The QC parameters are

  • QC KAPPA MEDIAN 11 (12, 21,22)
  • QC KAPPA STDEV 11 (12, 21,22)
  • Trending

    The median and the standard deviation of k11, k12, k21, k22 are plotted for the PRISM and the GRISM.