Science Operations

Data Reduction Pipelines

There are no observatory based and supported pipelines for the reduction of data from the 3 pairs of facility instruments: LBCB+LBCR, LUCI1+2 and MODS1+2. However, the MODS team have provided both a set of scripts (modsCCDRed) to remove instrumental signatures from MODS images and an IDL-based MODS data reduction pipeline Several widely-available pipelines have modules for the LBCs, MODS and LUCIs, and a few LBT users have developed data reduction software which they have made publicly available.

This page lists these reduction tools and provides links where you may find more information. If you know of any software packages missing from this page, or have any suggestions regarding reduction of data from these instruments, please let us know, at scienceops at lbto dot org.

LBC Data Reduction Tools

  • The INAF LBC data reduction pipeline,while not available for download, was described at the recent June 2017 Users’ Meeting.
  • LBC-reduction (a script to reduce LBC data, written by Benjamin Weiner, UA, and using IRAF, IDL, scamp and swarp. Most recently updated in 2013.)
  • LBC_Redux (similar to LBC-reduction but written by Neil Crighton, then at MPIA, and using python instead of IDL. Most recently updated in 2014.)

If you choose to reduce your data with standard packages, keep in mind that the LBC bias level varies, therefore the correct way to remove the bias offset is to use the overscan region. The overscan region extends over all rows and columns 2099-2304. However, near the bottom of the LBC Blue overscan region there is a discontinuity at the 50th column and a conservative region would be [2115:2300,1:4608]. Some LBCR biases show horizontal banding. It is always a good idea in visually inspect the calibrations before using them. Overscan-subtracted bias frames may be used to remove the remaining bias structure, which, except for the LBCR banding, is stable. See the LBC Calibrations page for more details.

MODS Data Reduction Tools

  • modsCCDRed — modsCCDRed is a collection of python scripts which process the MODS 2D full-frame CCD images (unbinned and binned).
    • While they perform basic tasks such as bias- (actually prescan-) subtraction, flat-fielding, they effectively deal with features that are unique to MODS, for example, the “even-odd” effect.
    • The modsCCDRed suite of scripts generates color-normalized flats and then bias-subtracts, flat-fields and corrects for bad pixels and columns in the full-frame spectroscopic images.
    • The scripts, along with installation instructions and a User Manual, are available at: http://www.astronomy.ohio-state.edu/MODS/Software/modsCCDRed and they are now (as of 02-02-2019) also distributed on GitHub:https://github.com/rwpogge/modsCCDRed
  • modsIDL — modsIDL is a suite of programs written in IDL for the reduction of MODS long-slit and multi-slit spectroscopy.
    • Until recently, it worked only for MODS1 spectra, both grating and prism, however a new release issued on 02-19-2019 extends it to MODS2 grating spectra.
    • The full modsIDL distribution is available for download, along with a User’s Manual, from http://www.astronomy.ohio-state.edu/MODS/Software/modsIDL/.
    • For users with earlier versions, an incremental release can be downloaded from the OSU MODS website linked above or from GitHub: https://github.com/rwpogge/modsIDL
    • When publishing results which made use of modsIDL, please include an acknowledgement following the guidelines given in the links above.
  • mods_quickreduce — A quick reduction tool installed on the mountain workstations which can be used to reduce MODS1 long-slit and MOS spectra.
  • SIPGI — INAF has released the pipeline which they have developed for the reduction of spectroscopic data from MODS and LUCI. Information about SIPGI can be found at this link.
  • PypeIt — a python package for semi-automated reduction of spectroscopic data from many observatories. PypeIt has modules for the reduction of MODS and LUCI spectra. More information about PypeIt may be found at this link.

LUCI Data Reduction Tools

  • FLAME is an IDL-based data reduction pipeline for LUCI, written by Sirio Belli (MPE).
    For an overview, see his Users’ Meeting presentation about FLAME. The paper by Belli, Contursi and Davies (2017) describes the pipeline more thoroughly and should be cited in works that make use of it.
  • telluric corrections —For telluric corrections, two tools which may be helpful are:
    • xtellcor —  the IDL-based xtellcorr, (Vacca, W., Cushing, M. and Rayner, J. 2003, PASP, 115, 389) which determines the telluric absorption by fitting the spectrum of an A0V star that is observed close in time and airmass to the target with a high-resolution model of Vega. xtellcorr_general is part of the IRTF’s Spextool package, but can be run as a standalone procedure in IDL; and
    • ESO’s molecfit. By request, molecfit has been installed on the mountain computers (we need to check this).
  • SIPGI — INAF has released the pipeline which they have developed for the reduction of spectroscopic data from MODS and LUCI. Information about SIPGI can be found at this link.
  • PypeIt — a python package for semi-automated reduction of spectroscopic data from many observatories. PypeIt has modules for the reduction of MODS and LUCI spectra. More information about PypeIt may be found at this link.