Quality Control: Beam

AMBER Quality Control:
Beam Position

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Beam_Pos


QC PLOTS
	CURRENT	HISTORY
BeamPos
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.

For AMBER, the setup is illuminated with a lamp and the characteristics of the beams (A/B/C) are monitored daily for the different configurations (shown bellow).

Only the configurations used presently in service mode observations (without BCD) are trended.

There are several trenplotter pages associated with this tutorial:

the Position references, which shows the XY coordinates and the shifts

The Flux, angle references which shows the integrated flux, the flux on the peak and the angle of the reference beams

The LAMP, in which the characteristics of the lamp are trended.

top Beam position

The beam alignement template records a set of 22 files in the different configurations. Each of these files contains an image of the AMBER instrument under different settings such as with or without the Beam Commuting Device (BCD). The following file shows the image of beam A in the K band without the BCD.

The 22 files are taken with the following setup:

The first file EXPNO 1 is the reference file with the cold stop in: QC.BeamPos.CLDSTP

file EXPNO 2: BCD out, Beam A, K band: QC.BeamPos.BA.K

file EXPNO 3: BCD out, Beam B, K band: QC.BeamPos.BB.K

file EXPNO 4: BCD out, Beam C, K band): QC.BeamPos.BC.K

files 5 6 and 7 are following the same sequence than 2, 3 and 4 with band H

files 8 9 10 same than 2 3 4 but with band J

files 11 to 19 are the same than 2 through 10 with the BCD in

file 20: BCD out, beam A, the fiber is bypassed, this file is used to monitor the lamp: QC.BeamPos.OUTF.BA

file 21: BCD out, beam B, the fiber is bypassed, this file is used to monitor the lamp: QC.BeamPos.OUTF.BB

file 22: BCD out, beam C, the fiber is bypassed, this file is used to monitor the lamp: QC.BeamPos.OUTF.BC

Pipeline assumptions:

- The beam is somewhat wider (in x) than 3-4 pixels
- The beam is no higher (in y) than ~30 pixels
- Beam pixels are brighter than 5 ADU (relative to local background)

Pipeline steps:

- The Bad Pixels have been filtered out
- The background is substracted from the image using a median filter
- Any hot or cold aread are fitered out using a smaller median filter
- Computes centroid and FWHM of pixels above threshold (iteratively, reducing the window size for each iteration)
- For each file, the following parameters are computed: X and Y coordinates of the image, size in X, size in Y, total Flux, Flux on the peak, angle of rotation of the object axis (of the two possible object axes (90 deg difference), this returned angle is always the one closest to the x-axis)
- The first file with the Cold Stop is used as a reference, for each of the additionnal files, the shifts in X and Y are calculated.
- The last 3 files (20-22 and 22) are used to monitor the lamp.

QC1 parameters

The QC1 parameters recorded in the QC1 database (table amber_bpos) and used for trending are as follow.

For the reference file: x_coldstop, y_coldstop, sizex_coldstop, sizey_coldstop, flux_coldstop, peakflux_coldstop, angle_coldstop

For the files taken without the BCD: x_noBCD_beamA/B/C_J/H/K, y_noBCD_beamA/B/C_J/H/K, sizex_noBCD_beamA/B/C_J/H/K, sizey_noBCD_beamA/B/C_J/H/K, flux_noBCD_beamA/B/C_J/H/K, peakflux_noBCD_beamA/B/C_J/H/K, angle_flux_noBCD_beamA/B/C_J/H/K

For the files taken without the BCD, 2 additionnal parameters are trended: shiftx_noBCD_beamA/B/C_J/H/K, shiftx_noBCD_beamA/B/C_J/H/K. These shifts are calculated between the position of the image in the present file and the reference file (cold stop)

For the files taken with the BCD, the parameters are the same the BCD: x_BCD_beamA/B/C_J/H/K, y_BCD_beamA/B/C_J/H/K, sizex_BCD_beamA/B/C_J/H/K, sizey_BCD_beamA/B/C_J/H/K, flux_BCD_beamA/B/C_J/H/K, peakflux_BCD_beamA/B/C_J/H/K, angle_flux_BCD_beamA/B/C_J/H/K

For the files taken with the BCD, 2 additionnal parameters are trended: shiftx_BCD_beamA/B/C_J/H/K, shifty_BCD_beamA/B/C_J/H/K. These shifts are calculated between the position of the image in the present file and the reference file (cold stop)

For the last files used to monitor the lamp: x_lamp_beamA/B/C, y_lamp_beamA/B/C, sizex_lamp_beamA/B/C, sizey_lamp_beamA/B/C, flux_lamp_beamA/B/C, peakflux_lamp_beamA/B/C, angle_lamp_beamA/B/C

Trending

History

Since the change of the polarizer in november 2008, there are 2 images on the detector and the flux in J and H for these 2 images is equivalent. The pipeline recipe cannot find the right image and set the flux and the position to zero. This is a known issue.