The visir_old_spc_wcal recipe

visir_old_spc_wcal

Synopsis

Old DRS detector: Spectroscopic wavelength calibration recipe

Description

This recipe estimates the dispersion relation using the atmospheric spectrum in a long-slit spectroscopy half-cycle frame.

The files listed in the Set Of Frames (sof-file) must be tagged: VISIR-Long-Slit-Spectroscopy-file.fits SPEC_CAL_LMR_WCAL VISIR-Quantum-Efficiency-Calibration-file.fits SPEC_CAL_QEFF VISIR-Atmospheric-Emission-Lines-Calibration-file.fits SPEC_CAL_LINES

Additionally, a bad pixel map with a PRO.CATG of SPEC_BPM may be added to the Set Of Frames with tag: BPM.

Constructor

cpl.Recipe("visir_old_spc_wcal")

Create an object for the recipe visir_old_spc_wcal.

import cpl
visir_old_spc_wcal = cpl.Recipe("visir_old_spc_wcal")

Parameters

visir_old_spc_wcal.param.auto_bpm

Automatic detection and correction of bad pixels (bool; default: True) [default=True].

visir_old_spc_wcal.param.plot

The recipe can produce a number of predefined plots. Zero means that none of the plots are produced, while increasing values (e.g. 1 or 2) increases the number of plots produced. If the plotting fails a warning is produced, and the recipe continues. The default behaviour of the plotting is to use gnuplot (with option -persist). The recipe currently produces 1D-plots using gnuplot commands. The recipe user can control the actual plotting-command used by the recipe to create the plot by setting the environment variable CPL_PLOTTER. Currently, if CPL_PLOTTER is set it must contain the string ‘gnuplot’. Setting it to ‘cat > my_gnuplot_$$.txt’ causes a number of ASCII-files to be created, which each produce a plot when given as standard input to gnuplot (e.g. later or on a different computer). A finer control of the plotting options can be obtained by writing an executable script, e.g. my_gnuplot.pl, that executes gnuplot after setting the desired gnuplot options (e.g. set terminal pslatex color) and then setting CPL_PLOTTER to my_gnuplot.pl. The predefined plots include plotting of images. Images can be plotted not only with gnuplot, but also using the pnm format. This is controlled with the environment variable CPL_IMAGER. If CPL_IMAGER is set to a string that does not contain the word gnuplot, the recipe will generate the plot in pnm format. E.g. setting CPL_IMAGER to ‘display - &’ will produce a gray-scale image using the image viewer display. (int; default: 0) [default=0].

visir_old_spc_wcal.param.slit_skew

Distortion correction: Skew of slit (degrees) (clockwise) (float; default: 0.52) [default=0.52].

visir_old_spc_wcal.param.spectrum_skew

Distortion correction: LMR Skew of spectrum (degrees) (counter- clockwise). Not used in High Resolution (float; default: 1.73) [default=1.73].

visir_old_spc_wcal.param.vert_arc

Distortion correction: LR Detector vertical curvature (pixel). Reduced by a factor 4 in MR. Not used in HR A-side. Increased by a factor 115/52 in HR B-side (float; default: -0.8) [default=-0.8].

visir_old_spc_wcal.param.hori_arc

Distortion correction: LMR Detector horizontal curvature (pixel). Increased by a factor 1.5 in HR A-side. Reduced by a factor 2 in HR B-side (float; default: 0.0) [default=0.0].

visir_old_spc_wcal.param.rl

Reject leftmost columns in spectrum extraction, zero means all columns on the left are used. In cross-dispersion mode a (small) negative number may be used (pixel) (int; default: 0) [default=0].

visir_old_spc_wcal.param.rr

Reject rightmost columns in spectrum extraction, zero means all columns on the right are used. In cross-dispersion mode a (small) negative number may be used (pixel) (int; default: 0) [default=0].

The following code snippet shows the default settings for the available parameters.

import cpl
visir_old_spc_wcal = cpl.Recipe("visir_old_spc_wcal")

visir_old_spc_wcal.param.auto_bpm = True
visir_old_spc_wcal.param.plot = 0
visir_old_spc_wcal.param.slit_skew = 0.52
visir_old_spc_wcal.param.spectrum_skew = 1.73
visir_old_spc_wcal.param.vert_arc = -0.8
visir_old_spc_wcal.param.hori_arc = 0.0
visir_old_spc_wcal.param.rl = 0
visir_old_spc_wcal.param.rr = 0

You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:

import cpl
visir_old_spc_wcal = cpl.Recipe("visir_old_spc_wcal")
[...]
res = visir_old_spc_wcal( ..., param = {"auto_bpm":True, "plot":0})

See also

cpl.Recipe for more information about the recipe object.

Bug reports

Please report any problems to Lars Lundin. Alternatively, you may send a report to the ESO User Support Department.