Quality Control: PSF standard star

SINFONI Quality Control:
PSF standard star frames

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general information | parameters trended


QC PLOTS
PSF:	CURRENT	HISTORY
net flux levels
strehl ratios
persistence (over-flux test)
offset from nominal center
image quality J-band
image quality H-band
image quality K-band
image quality H+K-band

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.

top General Information

PSF standard stars are not part of the general SINFONI calibration plan, but must be explicitly requested for a given programme by the PI. They can be used to define the PSF of the image and characterize any variation as a function of wavelength through the SINFONI data cube. In some cases, particularly when observing very faint science sources, the PSF star template is used as an offset position check. The PSF star data is processed with the same pipeline routine as is used for science frames. The PSF star products are stand-alone deliverables (i.e. no PSF correction or convolution is applied to the science data).

PSF standard star pipeline products include:

PRO.CATG	description
COADD_PSF	full cube coadded from jittered cubes
MASK_COADD_PSF	cube with weight factors
OBS_PSF	N object cubes before being coadded
PSF_CALIBRATOR_STACKED	N stacked object frames before being "cubed"
MASTER_PSF	median of collapsed COADD_PSF frame
AO_PERFORMANCE	table with extracted strehl ratios for each plane of the cube
ENC_ENERGY	table with extracted encircled energy

A SINFONI PSF standard star frame (this data has a PRO.CATG = PSF_CALIBRATOR_STACKED).

The median collapse of a PSF cube (this data has a PRO.CATG = MASTER_PSF).

top PSF standard star parameters trended

QC1 plots

The QC1 plots for the SINFONI PSF star trending are divided into two sections (PSF and image_quality). The QC1 PSF trending pages monitor the following:

PSF trending plots:

a test for an over-flux condition (>= 10,000 ADU) and, if detected, the number of affected pixels.
net flux (ADU/pixel) of PSF star over a 3 sigma aperture.
strehl ratio (median value over all wavelengths).
a test for an over-flux condition (>= 10,000 ADU) and, if detected, the number of affected pixels.
a measure of the radial offset from the nominal center (in pixels).

image_quality trending plots:

PSF star image quality (FWHM) as compared to the DIMM seeing which has been corrected to the same wavelength and airmass (J-band).
PSF star image quality (H-band).
PSF star image quality (K-band).
PSF star image quality (H+K band).

QC1 parameters

Parameter	Table: Name (QC1 database)	Description of Procedure
net flux level	sinfoni_psf: qc.net.flux	SExtractor (Bertin and Arnouts 1996 A&A 117,393) is run on the MED_COADD_PSF frame and the brightest detected source is assumed to be the PSF. The total flux integrated over a 3 sigma detection aperture is divided by the number of pixels in this aperture. This "net" flux per pixel is monitored for all filters and pixel scales. Values above 5 ADU/pixel are considered acceptable.
median strehl ratio	sinfoni_psf: qc.strehl.med	For each plane (wavelength step) in the COADD_PSF cube the pipeline computes the strehl ratio of the PSF star. The median value over all cube planes is monitored for all filters and pixel scales.
test for over-flux	sinfoni_psf: qc.persist.danger, qc.Npersist	A histogram is created from the PSF_CALIBRATOR_STACKED image. If there are more than 10 instances of 6 or more contiguous pixels having count levels above 10,000 ADU, then this frame is in danger of persistence. In this case qc.persist.danger = 1, otherwise it is set to 0. If a danger of persistence is detected, the number of affected pixels is also given (qc.Npersist).
measure of radial offset from nominal frame center	sinfoni_psf: qc.center.offset	The nominal center of the PSF star image is computed from the frame size: x0 = nx/2; y0 = ny/2 Based on the position of the PSF star (as detected by SExtractor in the QC script QCsinfo_psf.py) (x, y) the radial offset to the frame center is computed as: qc_center_offset = sqrt[ (x-x0)^2 + (y-y0)^2 ]. This is important since the PSF star is often used as a positioning test when faint science observations are made.
image quality (J-band)	sinfoni_psf: qc.delta.fwhm, qc.fwhm.sinfo	Delta_IQ = sinfoni PSF star FWHM - DIMM seeing (whereby the DIMM seeing has been adjusted to the wavelength and airmass of the PSF star observation). The image quality (IQ) plot shows the FWHM of the PSF star and the corrected DIMM plotted against one another. CLOSED loop (AO) observations are plotted as solid circles, while OPEN loop (non-AO) observations are shown as open circles (J-band with all pixel scales). NOTE: The conversion from pixels to arcsec for the image FWHM takes into account the fact that the reconstructed SINFONI cube has rectangular pixels. The reconstructed pixels are such that on-sky Delta_X = 0.5*Delta_Y. The correct conversion, in terms of the source position angle (PA), is: pixel_scale is given by the keyword INS.OPTI1.NAME.
image quality (H-band)	sinfoni_psf: qc.delta.fwhm, qc.fwhm.sinfo	As above. (H-band with all pixel scales).
image quality (K-band)	sinfoni_psf: qc.delta.fwhm, qc.fwhm.sinfo	As above. (K-band with all pixel scales).
image quality (H+K-band)	sinfoni_psf: qc.delta.fwhm, qc.fwhm.sinfo	As above. (H+K -band with all pixel scales).

QC Reports for PSF Standard Star Frames

QC Report 1 QC Report 2

QC Report 1:
UL: the PSF_CALIBRATOR_STACKED full detector intermediate product image with the number of saturated pixels listed.
UR: the MASTER_PSF median cube collapsed image. A number of paramters are listed for the brightest source detected: the source center (pixels), the integrated flux (within 3 sigma), the isophotal area (3 sigma), the net flux per pixel, the image FWHM (arcsec), the DIMM seeing corrected for the same airmass and filter used by this standard star, the status of the AO loop (OPEN or CLOSED), the position angle of the brightest source (degrees CCW from the x-axis), and its elongation and ellipticity. The source center, its position angle, and its FWHM are marked on the image.
LL: the (scaled) difference between two cube planes. Plane 100 - Plane 2072. The wavelengths of these planes are listed to the right of this image.
LR: a horizontal (blue line) and vertical (red line) cut through the center of the brightest detected source of the MASTER_PSF median cube collapsed image. The respective averages through this center are shown as dotted lines.

QC Report 2:
UL: three single column traces of the current product (PSF_CALIBRATOR_STACKED) through: x = 500 (dark grey), x = 1000 (middle grey), x = 1500 (light grey) and an averaged sum of all columns (blue).
UC: three single row traces of the current product (PSF_CALIBRATOR_STACKED) through: x = 500 (dark grey), x = 1000 (middle grey), x = 1500 (light grey) and an averaged sum of all rows (blue).
UR: the background-subtracted PSF star spectrum (PSF_STAR_SPECTRA) extracted by the pipeline.
LL: the relative encircled normalized energy as a function of radius from the source center (arcsec).
LC: the strehl ratio as a function of wavelength (microns). The median strehl ratio (dotted green line) and the area denoting the 1 sigma strehl ratio (shaded green area) are shown.
LR: a logarithmic histogram of the PSF_CALIBRATOR_STACKED full detector image is shown as a dark blue line, while the reflection of the non-positive flux histogram is shown in light blue.

QC Report 3 (only created if an over-flux is detected!)

QC Report 3
TOP: a logarithmic histogram of the PSF_CALIBRATOR_STACKED full detector science image with the persistence critical region shown as a red dotted line.
LL: the PSF_CALIBRATOR_STACKED full detector intermediate product image.
LR: an estimate of the location of possible persistence critical pixels.

A more technical description of the QC procedures used for the PSF stars can be found here.

Trending and Issues

History

Trending and scoring of SINFONI PSF standard star data began 2009-05-01.