Welcome to 4FS ETC’s documentation!

The 4FS_ETC is the software package used to fold (large numbers of) template spectra through the 4MOST system response, and optionally to assess whether the folded spectra have met specified success criteria.

The main usage of the package is in the 4MOST Facility Simulator (4FS).

Software documentation

• Introduction
  • Installation
  • Running the ETC tool
  • Estimating exposure times
  • Getting the instrument response
• Exposure Time Calculator description
  • ETC characteristic data
  • ETC sky
  • Signal to noise calculation
  • Galactic reddening
  • Airmass
• Command line tools
  • Catalogue processing
  • Debugging individual targets
• File formats
  • Survey configuration file
  • Target catalogue
  • Output catalogue
  • Rulesets file
  • Rules file
  • Template file
• API
  • Base class to handle spectra
  • Spectral templates
  • Filters
  • Atmospheric emission and absorption
  • Telescope simulation
  • Spectrograph simulation
  • Exposures
  • Observatories and observations
  • Rules and Rulesets
  • Exposure time calculation
  • Target catalog processing
  • Rebinning functions
  • Fiber fraction functions
  • Additional VEGA unit
  • Submodule to query the ESO ETC
  • Tools to query ESO skymodel
  • Level 1 pipeline data output
• ETC verification
  • Test #1: Coupling to fibre flux
  • Test #2: Re-binning and instrument convolving
  • Test #3: SNR scaling with exposure time
  • Test #4: Sky brightness
  • Test #5/7: “Real” spectra and end-to-end performance
  • Test #8: Extended source and airmass
• Changes
  • Version 2.6.1 (2023-07-16)
  • Version 2.6.0 (2023-07-12)
  • Version 2.5.2 (2023-12-04)
  • Version 2.5.1 (2023-11-23)
  • Version 2.5.0 (2023-11-10)
  • Version 2.4.0 (2023-04-17)
  • Version 2.3.0 (2023-02-01)
  • Version 2.2.2 (2022-12-16)
  • Version 2.2.1 (2022-12-07)
  • Version 2.2.0 (2022-11-02)
  • Version 2.1.0 (2022-07-12)
  • Version 2.0.5 (2022-07-01)
  • Version 2.0.4 (2021-12-20)
  • Version 2.0.3 (2021-11-18)
  • Version 2.0.2 (2021-10-28)
  • Version 2.0.1 (2021-07-28)
  • Version 0.7 (2021-06-25)

Development links

• Gitlab repository

• Jira ticket system

Relevant 4MOST documents

• ETC Requirements Specification, VIS-SPE-4MOST-47110-1740-0001

• Online-4FS user manual (including file format specification), VIS-MAN-4MOST-47110-1720-0001

• DMS Level 1 Pipeline DXU, VIS-TNO-4MOST-47110-0143-0001