FORS_WAVE_CALIB(7)

📦 version 5.5.7, in ubuntu jammy, ubuntu noble

💖 FORS_WAVE_CALIB(7) 💖

okay bestie, sit down, hydrate, because we're about to talk about fors_wave_calib — that's the manual page (section 7, fors recipes girlies rise) for the recipe that derives the dispersion relation from a rectified arc lamp frame. no cap, this one's a baddie.

✨ NAME ✨

fors_wave_calib — derive dispersion relation from rectified arc lamp frame. that's the whole job. that's the assignment. 💅

🌸 SYNOPSIS 🌸

esorex fors_wave_calib [OPTIONS] FILE.sof

yes bestie, that's it. esorex, the recipe name, your options, your .sof file. iconic format honestly.

🦋 DESCRIPTION 🦋

so this recipe wavelength-calibrates the MOS/MXU slit spectra that live inside the rectified arc lamp exposure you got from the recipe fors_extract_slits. it's giving glow-up for your arc lamp, fr fr.

a pattern-matching algorithm gets applied, exactly like in the recipe fors_detect_spectra. same energy, different day.

the input spatial map gets used to make the wavelength map. yes, they're connected. the way that one feeds the other?? obsessed.

🎀 heads up: use recipe fors_wave_calib_lss for LSS data, OR for MOS/MXU data where every single slit has the same offset. don't come for this recipe with that data, she's not built for it. for more details on this whole data reduction strategy, go read the FORS Pipeline User´s Manual.

also note: if you specify an input GRISM_TABLE, it will set some of the recipe configuration parameters to default values that are valid for a particular grism. it's like the grism table picks your outfit for you. slay.

and just so we're clear — in the table below, the acronym MXU can alternatively be read as MOS. same thing, different name, we love a flexible queen. 💜

📥 Input files

SPATIAL_MAP_MXU — Calib — Spatial map — Required: Y ✨
RECTIFIED_LAMP_MXU — Calib — Rectified arc exposure — Required: Y ✨
SLIT_LOCATION_MXU — Calib — Slit location table — Required: Y ✨
CURV_COEFF_MXU — Calib — Spectral curvature — Required: Y ✨
MASTER_LINECAT — Calib — Line catalog — Required: Y ✨
GRISM_TABLE — Calib — Grism table — Required: . (optional bestie, she's a maybe)

📤 Output files

REDUCED_LAMP_MXU — FITS image — Calibrated arc lamp exposure
DISP_COEFF_MXU — FITS table — Inverse dispersion coefficients
DISP_RESIDUALS_MXU — FITS image — Image of modeling residuals
WAVELENGTH_MAP_MXU — FITS image — Wavelengths mapped on CCD
SPECTRAL_RESOLUTION_MXU — FITS table — Spectral resolution table

five whole outputs?? she's productive. main character energy for real. 👑

💅 OPTIONS 💅

--dispersion <float> — expected spectral dispersion, in Angstrom/pixel. it's a float, default: 0.0. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.dispersion [default = 0.0].
--peakdetection <float> — initial peak detection threshold, in ADU. float, default: 0.0. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.peakdetection [default = 0.0].
--wdegree <int> — degree of the wavelength calibration polynomial. int, default: 0. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.wdegree [default = 0].
--wradius <int> — search radius when iterating pattern-matching with the first-guess method. int, default: 4. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.wradius [default = 4].
--wreject <float> — rejection threshold in the dispersion relation fit, in pixels. float, default: 0.7. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.wreject [default = 0.7].
--wcolumn <str> — name of the line catalog table column that holds the wavelengths. str, default: ´WLEN´. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.wcolumn [default = WLEN].
--startwavelength <float> — start wavelength in spectral extraction. float, default: 0.0. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.startwavelength [default = 0.0].
--endwavelength <float> — end wavelength in spectral extraction. float, default: 0.0. the full name of this option for the EsoRex configuration file is fors.fors_wave_calib.endwavelength [default = 0.0].

🌈 and guess what — you can literally create a configuration file containing all these options, with suitable default values and everything. for the deets, just go look at what the esorex --help command tells you. it's all there bestie, promise.

👀 SEE ALSO 👀

the full documentation for the fors pipeline can be downloaded as a PDF file using this URL:

ftp://ftp.eso.org/pub/dfs/pipelines/fors/fors-pipeline-manual-4.9.pdf

an overview over the existing ESO pipelines lives 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.

and fun fact 🍓 — you can 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 fors pipeline are: fors_align_sky(7), fors_align_sky_lss(7), fors_bias(7), fors_calib(7), fors_config(7), fors_dark(7), fors_detect_objects(7), fors_detect_spectra(7), fors_extract(7), fors_extract_objects(7), fors_extract_slits(7), fors_flatfield(7), fors_img_science(7), fors_img_screen_flat(7), fors_img_sky_flat(7), fors_normalise_flat(7), fors_photometry(7), fors_pmos_calib(7), fors_pmos_extract(7), fors_pmos_science(7), fors_remove_bias(7), fors_resample(7), fors_science(7), fors_spec_mflat(7), fors_subtract_sky(7), fors_subtract_sky_lss(7), fors_sumflux(7), fors_trace_flat(7), fors_wave_calib_lss(7), fors_zeropoint(7). it's a whole friend group, honestly. 🫶

⭐ VERSION ⭐

fors_wave_calib 5.5.7 — yes, that's the version, write it down bestie.

💖 AUTHOR 💖

Carlo Izzo <usd-help@eso.org>

😭 BUG REPORTS 😭

please report any problems to usd-help@eso.org. alternatively, you may send a report to the ESO User Support Department <usd-help@eso.org>. (same email, two vibes, both valid.)

📜 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 02110-1301 USA

okay that's the whole page bestie!! 🎀 this was fors_wave_calib version 5.5.7, from the fors recipes manual, section 7 — you ate that, go calibrate something 💅✨

📦 where this page comes from

ubuntu jammy: cpl-plugin-fors-doc 5.5.7+dfsg-2build1 · GPL-v2+
ubuntu noble: cpl-plugin-fors-doc 5.5.7+dfsg-2build1 · GPL-v2+
💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on 2026-10-18: a language model's rewrite of the original, under its terms