Create a calibration frame encoding the spectral position (i.e. wavelength) of each pixel on the detector.
This recipe creates the wavelength calibration frame needed for all three detectors. It must be called after the kmo_flat recipe, which generates the two spatial calibration frames needed in this recipe. As input a lamp-on frame, a lamp-off frame, the spatial calibration frames and the list with the reference arclines are required.An additional output frame is the resampled image of the reconstructed arc frame. All slitlets of all IFUs are aligned one next to the other. This frame serves for quality control. One can immediately see if the calibration was successful.
The lists of reference arclines are supposed to contain the lines for both available calibration arc-lamps, i.e. Argon and Neon. The list is supposed to be a F2L KMOS FITS file with three columns: 1. Reference wavelength 2. Relative strength 3. String either containing “Ar” or “Ne” The recipe extracts, based on the header keywords, either the applying argon and/or neon emission lines. Below are the plots of the emission lines for both argon and neon. The marked lines are the ones used for wavelength calibration.
Furthermore frames can be provided for several rotator angles. In this case the resulting calibration frames for each detector are repeatedly saved as extension for every angle.
DO KMOS
category Type Explanation Required #Frames
-------- ----- ----------- -------- -------
ARC_ON RAW Arclamp-on exposure Y >=1
ARC_OFF RAW Arclamp-off exposure Y 1
XCAL F2D x calibration frame Y 1
YCAL F2D y calibration frame Y 1
ARC_LIST F2L List of arclines Y 1
FLAT_EDGE F2L Fitted edge parameters Y 1
REF_LINES F2L Reference line table Y 1
WAVE_BAND F2L Table with start-/end-wavelengths Y 1
DO KMOS
category Type Explanation
-------- ----- -----------
LCAL F2D Wavelength calibration frame
(3 Extensions)
DET_IMG_WAVE F2D reconstructed arclamp-on exposure
(4 extensions: 3 detector images +
the arclines list table)
Create an object for the recipe kmo_wave_cal.
import cpl
kmo_wave_cal = cpl.Recipe("kmo_wave_cal")
The polynomial order to use for the fit of the wavelength solution. 0: (default) The appropriate order is chosen automatically depending on the waveband. Otherwise an order of 6 is recommended, except for IZ- band, there order 4 should be used (long; default: 0) [default=0].
Set this parameter to TRUE if the wavelengths are ascending on the detector from top to bottom. (bool; default: False) [default=False].
The expected dispersion of the wavelength in microns/pixel. If the default isn’t changed it will automatically be selected upon header keywords. (float; default: -1.0) [default=-1.0].
Suppress arbitrary filename extension.(TRUE (apply) or FALSE (don’t apply) (bool; default: False) [default=False].
The number of samples in wavelength for the reconstructed cube (long; default: 2048) [default=2048].
The lowest wavelength [um] to take into account when reconstructing (default of -1 sets the proper value for the actual band automatically) (float; default: -1.0) [default=-1.0].
The highest wavelength [um] to take into account when reconstructing (default of -1 sets the proper value for the actual band automatically) (float; default: -1.0) [default=-1.0].
The following code snippet shows the default settings for the available parameters.
import cpl
kmo_wave_cal = cpl.Recipe("kmo_wave_cal")
kmo_wave_cal.param.order = 0
kmo_wave_cal.param.dev_flip = False
kmo_wave_cal.param.dev_disp = -1.0
kmo_wave_cal.param.suppress_extension = False
kmo_wave_cal.param.b_samples = 2048
kmo_wave_cal.param.b_start = -1.0
kmo_wave_cal.param.b_end = -1.0
You may also set or overwrite some or all parameters by the recipe parameter param, as shown in the following example:
import cpl
kmo_wave_cal = cpl.Recipe("kmo_wave_cal")
[...]
res = kmo_wave_cal( ..., param = {"order":0, "dev_flip":False})
See also
cpl.Recipe for more information about the recipe object.
Please report any problems to Alex Agudo Berbel. Alternatively, you may send a report to the ESO User Support Department.
This file is part of the KMOS Instrument Pipeline Copyright (C) 2002,2003 European Southern Observatory
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
Code author: Alex Agudo Berbel <kmos-spark@mpe.mpg.de>