Quality Control: Image flats

ISAAC Quality Control:
Slit image

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grating check | acquisition | calObBuild


QC PLOTS
	CURRENT	HISTORY
grating check parameters
acquisition
day-time CalObBuild
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.

ISAAC through slit images are taken to check that the spectroscopy entrance slit (and hence the whole spectrum as such) is reliably projected on a certain position on the detector. Through slit images are taken for three purposes:

top grating check

At the beginning of the night, as part of the daily health check procedure an arc frame is taken with the setting SW MR SH 1.4097; the spectrum is dominated by one strong isolated central arc line with a curved shape. The frame is submitted to the slit pos recipe.

QC1 parameters

parameter	QC1 database: table, name	procedure
x-position	isaac_slit, qc_slit_x, qc_slit_y, qc_slit_a, qc_slit_f	- search for the brightest feature in the center of the detector and fit a rotated rectangle - return x-position of rectangle center
y-position	isaac_slit, qc_slit_y	- return y-position of rectangle center
angle	isaac_slit, qc_slit_a	- return rotation angle of the fit rectangle
flux	isaac_slit, qc_slit_f	- return total flux within the rectabgle area

Trending

The grating check template generates an Argon line spectrum around a bright isolated arc line using the setup SW MR SH 1.4097 and Argon lamp. The projected shape of the image is a curved rectangle. Although the slit recipe is desinged to retrieve some of geometric parameters from the shape of a slit image (it is a rectangle) of the slit mask , the recipe nevertheless returns reliable values for the position (x and y) and Argon lamp flux (f) for the considered arc line. The fit parameter slit angle is not reliable, as a curved line is fit by a straight line model.

History

The grating check is monitored since 2006-10-01. The slit QC1 parameters of the grating check application are indicated in the QC1 database by operat_type=GratingCentralLine.

2007-04-18: Since 2007-02-12 the new Y-position value is around 545
2007-06-26 to 2007-07-01: intervention; (before intervention values) POS_X = 527.7, POS_Y = 543, FLUX = 2.9 E+06
2007-06-26 to 2007-07-01 intervention

2007-07-20 to 2007-07-30 intervention

2007-08-11 Hawaii detector blackout event

top acquisition

For reasons to align the objective (the camera) before a spectroscopic observation (calibration star or science spectrum) several through slit images are taken by the acquisition template.

QC1 parameters

The definition of QC1 parameters are identical to the grating check application:

parameter	QC1 database: table, name	procedure
x-position	isaac_slit, qc_slit_x, qc_slit_y, qc_slit_a, qc_slit_f	- search for the brightest feature in the center of the detector and fit a rotated rectangle - return x-position of rectangle center
y-position	isaac_slit, qc_slit_y	- return y-position of rectangle center
angle	isaac_slit, qc_slit_a	- return rotation angle of the fit rectangle
flux	isaac_slit, qc_slit_f	- return total flux within the rectangle area

Trending

The first frame of the acquisition template is an image with TPL.EXPNO=1.The second frame of the acquisition template is the first through slit image with TPL.EXPNO=2 followed by an unpredictable number of further through slit images as part of the iterative manual alignment procedure. The parameters of the first through slit image indicate the slit wheel biases after the last alignment. All acquisition slit images are quality checked and are ingested in the QC1 database, but only the parameters of the first through slit image (filtered via TPL.EXPNO=2) are given in the trending plots to monitor the offset positions of the slit mask wheel.

History

The camera check is monitored since 2004-03-12. The slit QC1 parameters of the camera check application are indicated in the QC1 database by operat_type=ALIGN.

top calObBuild

Through slit images are taken as part of the daytime calibrations; one is taken BEFORE and a second one is taken AFTER the spectroscopic daytime calibrations to ensure that the camera, and the slit positions are stable during the batch execution.

QC1 parameters

The definition of QC1 parameters are identical to the grating check application. In addition to the ones derived by the pipeline recipe we construct differential parameters:

Day-time CalOBuild trough Slit images: with DPRs = TEST SLIT IMAGE, absolute QC values derived from the isaac_img_slitpos recipe. Only through slit images taken as part of the day-time calibration batch (called CalOBuild) are used. All other through list images as part of the acquisition or other technical alignment tests are ignored. The constant setting of these frames is defined via: SW-arm, hence INS.OPTI1.NAME=S2; 0.3'' slit, filter=Ks, DoubleCorr read mode, DIT=1.7725666, and NDIT=1.
Day-time CalOBuild trough Slit images: with DPRs = TEST SLIT IMAGE, difference QC values derived from the isaac_spc_slitpos recipe. Only through slit images taken as part of the day-time calibration batch (called CalOBuild) are used. All other through list images as part of the acquisition or other technical alignment tests are ignored. Complete pairs of 'BEFORE' and 'AFTER' through slit images are generated on the fly and the difference e.g. Delta-X = X-position(AFTER) - X-position(BEFORE) are generated and trended. The given time is the average time of both BEFORE and AFTER slit images.

parameter	QC1 database: table, name	procedure
x-position	isaac_slit, qc_slit_x, qc_slit_y, qc_slit_a, qc_slit_f	- search for the brightest feature in the center of the detector and fit a rotated rectangle - return x-position of rectangle center
y-position	isaac_slit, qc_slit_y	- return y-position of rectangle center
angle	isaac_slit, qc_slit_a	- return rotation angle of the fit rectangle
flux	isaac_slit, qc_slit_f	- return total flux within the rectangle area

Trending

The slit QC1 parameters of the CalObuild check application are indicated in the QC1 database by operat_type=BEFORE and operat_type=AFTER. The difference qc parameters are not ingested in the QC1 database. They are calculated on the fly when the plot is generated.

History

The CalObuild slit images are monitored since 2005-04-12.