


QC PLOTS 

CURRENT 
HISTORY 
optical distortion 


effective optical distortion 


grating, dispersion 


arc lamps 


QC1 database (advanced users):
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Click on CURRENT to see the current trending (Health Check).
Click on HISTORY to see the historical evolution of the trending. 
Arc calibrations come for two gratings (LR and MR) and two instrument arms (SW and LW), thus one may find the following abbreviations:
 SSAL short wavelength spectroscopy arcs using the LR grating
 SSAM short wavelength spectroscopy arcs using the MR grating
 LSAL long wavelength spectroscopy arcs using the LR grating
 LSAM long wavelength spectroscopy arcs using the MR grating
The isaacp arc recipe was considerably improved and was put in operation for data taken after 20031120. The arc recipe produces two kind of coefficients: a) the wavelength dispersion coefficients (3 parameters) and b) the optical distortion in xdirection for the whole field of view (6 parameters).
The QC parameters for the wavelength solution are : QC.DISPC01, QC.DISPC02 and QC.DISPC03, where
lambda=QC.DISPC01 + X * QC.DISPC02 + X * X * QC.DISPC03 + X * X * X * QC.DISPC04
holds. The QC parameter of the optical distortion in x directions are related via :
DeltaX=QC.DIST1 + X * QC.DISTX + Y * QC.DISTY + X * Y * QC.DISTXY + X * X * QC.DISTXX + Y * Y * QC.DISTYY
The QC parameters of the optical distortion in ydirection are derived from a different kind of calibrations: startrace frames.
The LR grating recipe generates two products, one for the Ar lamp and one for the Xe lamp separately.
The MR grating recipe generates one product with lines of both lamps.
The pipeline recipe processes the arc frames in two parts. The first part is on the arc line detection and the correction of the optical distortion in xdirection. The second part is on the arc line identification via the arc line catalog and calculating the nonlinear wavelength dispersion transformation.
QC1 parameters
parameter 
QC1 database: table, name 
procedure 
optical distortion coefficients
SWarm
LWarm 
isaac_arc, qc_dist1, qc_distx, qc_disty, qc_distxx, qc_distxy, qc_distyy 
 After arc lines have been detected the curvature is modeled by a polynomial and correct to get straight lines. At least three emission lines must be detected. The polynomial describes the optical distortion in xdirection only. The optical distortion correction in ydirection is not required in this calibration step. See startrace calibrations for details on the optical distortion in ydirection. 
effective optical distortions
SWarm
LWarm 

 As good practice the optical distortion coefficients are applied to five selected points in the FOV. These are the four detector quadrant centers (ul,ur, ll, lr) and the center of the detector (cc). These effective distortions are not stored in the DB. They are calculated on the fly, when the health check plot is updated. 
arc line number 
isaac_arc, qc_arcs_num 
 the number of detected arc lines 
number of arc lines with fwhm 
isaac_arc, qc_arcs_numgood 
 the number of detected arc line for which a fwhm could be calculated 
FWHM 
isaac_arc, qc_fwhm_med 
 the median fwhm of qc_arcs_numgood arc lines 
top
wavelength dispersion parameters 
Example QC reports showing the arc line spectrum (red) and the catalog lines with their relative strength (blue symbols) for the setting SW LR SK are given once for the
Xenon lamp and once for the Argon lamp .
QC1 parameters
parameter 
QC1 database: table, name 
procedure 
wavelength of first pixel 
isaac_arc, qc_dispco1 
 offset coefficient of the wavelength dispersion solution 
dispersion 
isaac_arc, qc_dispco2 
 linear coefficient of the wavelength dispersion solution 
nonlinear dispersion 
isaac_arc, qc_dispco3 
 quadratic term of the wavelength dispersion solution 
nonlinear dispersion 
isaac_arc, qc_dispco4 
 cubic term of the wavelength dispersion solution 
wavelength of pixel 512 
isaac_arc, qc_wlen 
 central wavelength 
correlation factor 
isaac_arc, qc_xcorr 
 the correlation coefficient of the pattern matching algorithm. qc_xcorr >= 50% means the correct solution is found. qc_xcorr >=90% means the errorbars of the fit are very small. 
solution quality 
isaac_arc, qc_disp_stdev 
 standard deviation of the line position differences 
lines in catalog 
isaac_arc, qc_disp_numcat 
 number of arc lines in the catalog within wavelength range 
used lines for correlation 
isaac_arc, qc_disp_match 
 number of arc lines in the catalog within wavelength range used for the correlation 
grating offset 
isaac_arc, qc_pixoff 
 grating offset in pixel (difference between QC.WLEN and INS.GRAT.WLEN) 
resolving power 
isaac_arc, qc_respow 
 resolving power (QC.WLEN / QC.FWHM.MED) 
arc line flux 
isaac_arc, qc_arc_line_flux 
 resolving the post pipeline script searches for each of the four SWLR settings a certain xenon and an argon arc line and extracts the flux from the pipeline product table. The used lines are:
Argon 1.054810 mu (SWLRSZ)
Argon 1.208810 mu (SWLRJ)
Argon 1.744926 mu (SWLRSH)
Argon 2.313952 mu (SWLRSK)
Xenon 1.202994 mu (SWLRJ)
Xenon 1.510384 mu (SWLRSH)
Xenon 2.380295 mu (SWLRSK) 
Trending
The following relations between different QC1 parameters are trended:
