UVES_CAL_TFLAT(7)

📦

version 6.1.8 · 2 versions

6.1.8 · debian bookworm, ubuntu noble (latest)
6.1.6 · ubuntu jammy

💅 UVES_CAL_TFLAT 💅

okay bestie, welcome to UVES_CAL_TFLAT(7) — yeah, that's the manual page, and yeah, it lives in the uves recipes corner of the manual universe. this one's about uves_cal_tflat, and it's a whole journey. grab a strawberry 🍓, we're doing this.

✨ NAME ✨

uves_cal_tflat — reduces a TFLAT frame. that's it, that's the whole name. slay.

🦋 SYNOPSIS 🦋

esorex uves_cal_tflat [OPTIONS] FILE.sof

like, that's the vibe. esorex, the recipe name, whatever [OPTIONS] you're feeling, and your .sof file. periodt.

🌸 DESCRIPTION 🌸

so this recipe reduces a TFLAT_xxx frame, where xxx is either BLUE or RED. it does the whole thing in two moves:

it combines all the provided TFLAT frames into one MASTER_TFLAT frame, then
it does a totally normal science reduction on the first input TFLAT frame.

the input frames you're feeding it are raw TFLAT_xxx frames, and also:

order table(s) for each chip, ORDER_TABLE_xxxx (where xxxx = BLUE, REDL, REDU)
line table(s) for each chip, LINE_TABLE_xxxx
a master bias frame, MASTER_BIAS_xxxx
a master flat, MASTER_FLAT_xxxx

that's the roster. no cap. 💖

👑 OPTIONS 👑

bestie there are a LOT of these and i'm not skipping a single one. every option also has a full name for the EsoRex configuration file, and i'm giving you both, because that's the whole point. 🫶

--backsub.mmethod <str> — the background measuring method. if it's median, the background gets sampled using the median of a subwindow. if it's minimum, it uses the subwindow's minimum value instead. if it's no, no background subtraction happens at all. (type: str; default: median.) full name for the EsoRex config file: uves_cal_tflat.backsub.mmethod [default = median].
--backsub.npoints <int> — the number of columns in interorder space that get used to sample the background. (type: int; default: 82.) full name for the EsoRex config file: uves_cal_tflat.backsub.npoints [default = 82].
--backsub.radiusy <int> — the height, in pixels, of the background sampling window, and it's (2*radiusy + 1). heads up: this parameter is not corrected for binning. (type: int; default: 2.) full name for the EsoRex config file: uves_cal_tflat.backsub.radiusy [default = 2].
--backsub.sdegree <int> — the degree of the interpolating splines. rn only degree = 1 is supported. (type: int; default: 1.) full name for the EsoRex config file: uves_cal_tflat.backsub.sdegree [default = 1].
--backsub.smoothx <float> — if spline interpolation is being used to measure the background, the x-radius of the post-smoothing window is (smoothx * image_width). and image_width here means the image width after binning. if it's negative, the default values kick in: (25.0/4096) for blue flat-field frames, (50.0/4096) for red flat-field frames, (300.0/4096) for blue science frames, and (300.0/4096) for red science frames. (type: float; default: -1.0.) full name for the EsoRex config file: uves_cal_tflat.backsub.smoothx [default = -1.0].
--backsub.smoothy <float> — same deal but the y-axis: if spline interpolation is used to measure the background, the y-radius of the post-smoothing window is (smoothy * image_height), where image_height is the image height after binning. if it's negative, defaults are used: (100.0/2048) for blue flat-field frames, (300.0/2048) for red flat-field frames, (200.0/2048) for blue science frames, and (500.0/2048) for red science frames. (type: float; default: -1.0.) full name for the EsoRex config file: uves_cal_tflat.backsub.smoothy [default = -1.0].
--clean_traps <bool> — clean detector traps. if TRUE, detector traps get interpolated. the bad pixels are replaced by the average of the nearest good pixels in the same column, or they're simply marked as bad. the positions of bad pixels are hard-coded (as a function of the UVES chip). (type: bool; default: False.) full name for the EsoRex config file: uves_cal_tflat.clean_traps [default = False].
--debug <bool> — whether or not to save intermediate results to the local directory. (type: bool; default: False.) full name for the EsoRex config file: uves.debug [default = False].
--norm_method <str> — the method used to build the master frame. (type: str; default: explevel.) full name for the EsoRex config file: uves_cal_tflat.norm_method [default = explevel].
--plotter <str> — any plots the recipe makes get redirected to whatever command you put here. the plotting command must contain the substring gnuplot, and it has to be able to parse gnuplot syntax on its standard input. valid examples include gnuplot -persist and cat > mygnuplot$$.gp. if you want finer control over the plotting options, write an executable script — like my_gnuplot.pl — that runs gnuplot after setting the gnuplot options you want (e.g. set terminal pslatex color). to turn plotting off completely, set this parameter to no. (type: str; default: no.) full name for the EsoRex config file: uves.plotter [default = no].
--process_chip <str> — for RED arm data, process the redl chip, the redu chip, or both. (type: str; default: both.) full name for the EsoRex config file: uves.process_chip [default = both].
--reduce.backsub.mmethod <str> — background measuring method. if it's median, the background is sampled using the median of a subwindow. if it's minimum, the subwindow minimum value is used. if it's no, no background subtraction is done. (type: str; default: median.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.mmethod [default = median].
--reduce.backsub.npoints <int> — the number of columns in interorder space used to sample the background. (type: int; default: 82.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.npoints [default = 82].
--reduce.backsub.radiusy <int> — the height (in pixels) of the background sampling window is (2*radiusy + 1). this parameter is not corrected for binning. (type: int; default: 2.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.radiusy [default = 2].
--reduce.backsub.sdegree <int> — degree of interpolating splines. currently only degree = 1 is supported. (type: int; default: 1.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.sdegree [default = 1].
--reduce.backsub.smoothx <float> — if spline interpolation is used to measure the background, the x-radius of the post-smoothing window is (smoothx * image_width), where image_width is the image width after binning. if negative, the defaults are: (25.0/4096) for blue flat-field frames, (50.0/4096) for red flat-field frames, (300.0/4096) for blue science frames and (300.0/4096) for red science frames. (type: float; default: -1.0.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.smoothx [default = -1.0].
--reduce.backsub.smoothy <float> — if spline interpolation is used to measure the background, the y-radius of the post-smoothing window is (smoothy * image_height), where image_height is the image height after binning. if negative, the defaults are: (100.0/2048) for blue flat-field frames, (300.0/2048) for red flat-field frames, (200.0/2048) for blue science frames and (500.0/2048) for red science frames. (type: float; default: -1.0.) full name for the EsoRex config file: uves_cal_tflat.reduce.backsub.smoothy [default = -1.0].
--reduce.extract.best <bool> — (optimal extraction only) if false (fastest), the spectrum is extracted only once. if true (best), the spectrum gets extracted twice — the second time using improved variance estimates based on the first iteration. better variance estimates slightly improve the signal to noise you get, but at the cost of increased execution time. (type: bool; default: True.) full name for the EsoRex config file: uves_cal_tflat.reduce.extract.best [default = True].
--reduce.extract.chunk <int> — in optimal extraction mode, the chunk size (in pixels) used for fitting the analytical profile. why? because fitting the analytical profile to single bins would suffer from low statistics. (type: int; default: 32.) full name for the EsoRex config file: uves_cal_tflat.reduce.extract.chunk [default = 32].
--reduce.extract.kappa <float> — in optimal extraction mode, this is the threshold for bad (i.e. hot/cold) pixel rejection. if a pixel deviates more than kappa*sigma from the inferred spatial profile (where sigma is the uncertainty of the pixel flux), its weight gets set to zero. range: [-1,100]. if this parameter is negative, no rejection is performed. (type: float; default: 10.0.) full name for the EsoRex config file: uves_cal_tflat.reduce.extract.kappa [default = 10.0].
--reduce.extract.method <str> — extraction method. important caveats here bestie, read carefully: 2d/optimal are not supported by uves_cal_wavecal, weighted is supported only by uves_cal_wavecal, and 2d is not supported by uves_cal_response. (type: str; default: average.) full name for the EsoRex config file: uves_cal_tflat.reduce.extract.method [default = average].
--reduce.extract.oversample <int> — the oversampling factor used for the virtual resampling algorithm. if negative, the value 5 is used for S/N <=200, and the value 10 is used if the estimated S/N is > 200. (type: int; default: -1.) full name for the EsoRex config file: uves_cal_tflat.reduce.extract.oversample [default = -1].
--reduce.extract.profile <str> — okay so when you're in optimal extraction mode, this is the vibe of the profile you wanna use. gauss gives you a Gaussian profile. moffat gives you a Moffat profile with beta=4 plus a possible linear sky contribution. virtual uses a virtual resampling algorithm (like, it measures and then uses the actual object profile). constant assumes a constant spatial profile and lets you do optimal extraction of wavelength calibration frames. auto will automatically pick the best method based on the estimated S/N of the object. For low S/N, moffat or gauss are recommended (for robustness, bestie 💪). For high S/N, virtual is recommended (for accuracy ✨). Heads up: with virtual resampling you need a precise determination of the order positions, so the order-definition gets repeated using the (assumed non-low S/N) science frame. (str; default: auto). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.extract.profile [default = auto].
--reduce.extract.skymethod <str> — in optimal extraction mode, the sky subtraction method to use. median estimates the sky as the median of pixels along the slit (ignoring pixels close to the object), whereas optimal does a chi square minimization along the slit to obtain the best combined object and sky levels. The optimal method gives the most accurate sky determination but is also a bit slower than the median method (str; default: optimal). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.extract.skymethod [default = optimal].
--reduce.ffmethod <str> — flat-fielding method, bestie. If you set it to pixel, flat-fielding is done in pixel-pixel space (before extraction); if you set it to extract, flat-fielding is performed in pixel-order space (i.e. after extraction). If you set it to no, no flat-field correction is done at all — and in that case reduce.rebin.scale should be set to true to ensure flux conservation (both for response and science data) (str; default: extract). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.ffmethod [default = extract].
--reduce.merge <str> — order merging method 🫶. If optimal, the flux in the overlapping region is set to the (optimally computed, using the uncertainties) average of single order spectra. If sum, the flux in the overlapping region is computed as the sum of the single order spectra. If noappend the spectrum is simply rebinned but not merged. If flat-fielding is done, method optimal is recommended, otherwise sum. (str; default: optimal). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.merge [default = optimal].
--reduce.merge_delt1 <float> — order merging left hand (short wavelength) cut ✂️. To reduce the amount of order overlapping regions we allow to cut short and long wavelength ranges. This may reduce the ripple possibly introduced by the order merging. Suggested values are: 10 (W<=390), 12 (390<W<=437, 520<W<=564), 14 (437<W<=520, 564<W) (float; default: 0.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.merge_delt1 [default = 0.0].
--reduce.merge_delt2 <float> — order merging right hand (long wavelength) cut ✂️. To reduce the amount of order overlapping regions we allow to cut short and long wavelength ranges. This may reduce the ripple possibly introduced by the order merging. Suggested values is 4 (float; default: 0.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.merge_delt2 [default = 0.0].
--reduce.objoffset <float> — offset (in pixels) of extraction slit with respect to center of order. For optimal extraction the full slit is offset. For linear/average extraction, reduce.objoffset is ignored if reduce.objslit [default -1.0] is negative. In this case the offset is automatically determined by measuring the actual object position. (float; default: 0.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.objoffset [default = 0.0].
--reduce.objslit <float> — object window size (in pixels), ignored for optimal extraction 🙈. The value must be smaller than the total slit length. If negative, the default value (half of full slit length) is used. The upper and lower sky windows are defined as the part of the full slit (if any) outside the object window. The center of the object window is determined by the offset parameter. (float; default: -1.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.objslit [default = -1.0].
--reduce.rebin.scale <bool> — whether or not to multiply by the factor dx/dlambda (pixels per wavelength) during the rebinning to conserve the flux. This option is disabled as default because applying the flat field correction already ensures flux conservation. So like, this parameter should be TRUE (for response and science data) only if reduce.ffmethd = no. (bool; default: False). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.rebin.scale [default = False].
--reduce.rebin.wavestep <float> — the bin size used for BLUE/REDL data (in w.l.u.) in wavelength space. If negative, a step size of 2/3 * ( average pixel size ) is used. (float; default: -1.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.rebin.wavestep [default = -1.0].
--reduce.rebin.wavestep_redu <float> — the bin size used for REDU data (in w.l.u.) in wavelength space. If negative, a step size of 2/3 * ( average pixel size ) is used. (float; default: -1.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.rebin.wavestep_redu [default = -1.0].
--reduce.skysub <bool> — do sky-subtraction (only applicable to linear and average extractions)? (bool; default: False). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.skysub [default = False].
--reduce.slitlength <float> — extraction slit length (in pixels). If negative, the value inferred from the raw frame header is used (float; default: -1.0). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.slitlength [default = -1.0].
--reduce.tiltcorr <bool> — if enabled (recommended 💅), the provided dispersion solutions obtained at different slit positions are interpolated linearly at the actually measured position of the object/sky. Line tilt correction is currently not supported for 2d extraction, in which case the dispersion solution obtained at the middle of the slit is always used. (bool; default: True). The full name of this option for the EsoRex configuration file is uves_cal_tflat.reduce.tiltcorr [default = True].

Note that it is possible to create a configuration file containing these options, along with suitable default values. Please refer to the details provided by the esorex --help command. 👑

🌈 SEE ALSO 🌈

The full documentation for the uves pipeline can be downloaded as a PDF file using the following URL:

ftp://ftp.eso.org/pub/dfs/pipelines/uves/uves-pipeline-manual-6.1.8.pdf

An overview over the existing ESO pipelines can be found on the web page https://www.eso.org/sci/software/pipelines/.

Basic documentation about the EsoRex program can be found at the esorex (1) man page.

It is possible to call the pipelines from python using the python-cpl package. See https://packages.python.org/python-cpl/index.html for further information.

The other recipes of the uves pipeline are flames_cal_mkmaster(7), flames_cal_orderpos(7), flames_cal_predict(7), flames_cal_prep_sff_ofpos(7), flames_cal_wavecal(7), flames_obs_redchain(7), flames_obs_scired(7), flames_utl_unpack(7), uves_cal_cd_align(7), uves_cal_mbias(7), uves_cal_mdark(7), uves_cal_mflat(7), uves_cal_mflat_combine(7), uves_cal_mkmaster(7), uves_cal_orderpos(7), uves_cal_predict(7), uves_cal_response(7), uves_cal_wavecal(7), uves_obs_redchain(7), uves_obs_scired(7), uves_utl_ima_arith(7), uves_utl_remove_crh_single(7).

💜 VERSION 💜

uves_cal_tflat 6.1.8

👑 AUTHOR 👑

Jonas M. Larsen <cpl@eso.org>

🐛 BUG REPORTS 🐛

Please report any problems to cpl@eso.org. Alternatively, you may send a report to the ESO User Support Department <usd-help@eso.org>.

📜 LICENSE 📜

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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1307 USA

and that's the whole page, bestie!! 🎀 you just read uves_cal_tflat version 6.1.8, page UVES_CAL_TFLAT(7) — go forth and flat-field like the main character you are 💖✨🦋

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debian bookworm: cpl-plugin-uves-doc 6.1.8+dfsg-2 · GPL-v2+
ubuntu noble: cpl-plugin-uves-doc 6.1.8+dfsg-2build3 · GPL-v2+
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