VISIR_UTIL_DETECT_SHIFT(7)

✨ visir_util_detect_shift ✨

okay so bestie, welcome to visir_util_detect_shift — it's a visir recipe, it's from 2012, and it's literally the girl who finds your beams and calls out the bad images. periodt.

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🌸 SYNOPSIS 🌸

esorex visir_util_detect_shift [OPTIONS] FILE.sof

like, that's the whole vibe. you run it through esorex, you feed it a sof file, and she does her thing 💅

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🦋 DESCRIPTION 🦋

so what she does is: she detects beams in a background subtracted multi-beam image, then she figures out the shifts between the different images and their correlation. and if an image's correlation is giving nothing but red flags? she can reject it. no cap.

The files listed in the Set Of Frames (sof-file) must be tagged:

• VISIR-chopnod-corrected-file.fits BKG_CORRECTED
• bad-pixel-mask.fits STATIC_MASK

The output consists of single beam images of the size of the throw. The shifts will be written int CRPIX[12].

(yes, "int" — that's what it says, we don't fix typos around here, we respect the original 😌)

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💖 OPTIONS 💖

• --template <str> — Correlation template used to detect shifts and reject bad images. If none given an averaged image is used (str; default: ´NONE´). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.template [default = NONE].
• --min-correlation <float> — Minimal correlation to the template required to be accepted (float; default: 0.5). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.min-correlation [default = 0.5].
• --max-shift <float> — Maximal allowed object shift for an image to be accepted (float; default: 10.0). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.max-shift [default = 10.0].
• --max-mad <float> — Maximal allowed median absolute deviation for an image to be accepted. <= 0 equals no limit (float; default: 0.0). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.max-mad [default = 0.0].
• --naverage <int> — Number of planes to average before attempting to detect the shifts. (int; default: 1). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.naverage [default = 1].
• --method <str> — Method to determine beam shifts. xcorrelate: use the cross correlation shift. brightest: use the position of the brightest pixel (str; default: ´xcorrelate´). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.method [default = xcorrelate].
• --no-shift <bool> — Sets whether to apply the determined shifts in following recipes. Set to TRUE of shifts appear too large. (bool; default: False). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.no-shift [default = False].
• --no-reject <bool> — If true images with bad statistics will not be rejected and no shift correction is done (bool; default: True). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.no-reject [default = True].
• --beampos <str> — Define the positions of the beams. These positions are cut by the window to extract the single beam images. Format: sign:x,y,window;sign:x,y,window;... where sign is "pos" or "neg" depending on whether the beam is positive or negative. The window is optional and defines the size of the cut image around the beam. The default window is the chop throw. E.g.: pos:50,60;neg:50,160; By default autodetection is attempted. (str; default: ´NONE´). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.beampos [default = NONE].
• --eccmax <float> — The maximum eccentricity allowed in the combination of the three (in parallel nod/chopping) or four (in perpendicular nod/chopping) beams. In parallel mode, three perfectly aligned points spaced with the chopnod throw will have eccentricity 0, while in perpedicular mode a square with the chopnod throw as the side length will have eccentricity 0 (float; default: 3.0). The full name of this option for the EsoRex configuration file is visir.visir_util_detect_shift.eccmax [default = 3.0].

ngl bestie, you can totally make a configuration file holding all these options with their cute little defaults. just go peek at what esorex --help tells you. she explains it better than me fr fr 🫶

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🔥 SEE ALSO 🔥

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

ftp://ftp.eso.org/pub/dfs/pipelines/visir/visir-pipeline-manual-1.4.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 visir pipeline are visir_img_dark(7), visir_img_ff(7), visir_img_reduce(7), visir_img_trans(7), visir_old_img_combine(7), visir_old_img_phot(7), visir_old_spc_obs(7), visir_old_spc_obs_ech(7), visir_old_spc_phot(7), visir_old_spc_phot_ech(7), visir_old_spc_wcal(7), visir_old_spc_wcal_ech(7), visir_old_util_destripe(7), visir_spc_reduce(7), visir_util_apply_calib(7), visir_util_clip(7), visir_util_convert_weight(7), visir_util_img_std_cat(7), visir_util_join(7), visir_util_qc(7), visir_util_repack(7), visir_util_run_swarp(7), visir_util_spc_std_cat(7), visir_util_spc_txt2fits(7), visir_util_undistort(7)

like, the whole friend group 💜

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⭐ VERSION ⭐

visir_util_detect_shift 4.4.2

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👑 AUTHOR 👑

Find beam positions and reject bad images <Julian Tayor>

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🎀 BUG REPORTS 🎀

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

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🌈 LICENSE 🌈

This file is part of the VISIR Instrument Pipeline Copyright (C) https://support.eso.org 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, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02111-1307 USA

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and that's the whole thing bestie 🫶 visir_util_detect_shift version 4.4.2, from the VISIR recipes, and she ate 💅✨ go detect some beams, ily, bye 🦋