SALT - Southern African Large Telescope

SALT Calibration Plan


General information:

All SALT calibration data are divided into four categories:

  1. Default calibration (DC):
    • will be produced for every observable night
    • will be produced without ANY PI request
    • PI does not charged for that
    • will be done during day or morning time, possibly twilight and night time
  2. Library Calibrations (LC):
    • will be produced not every observable night, but with some regular interval
    • will be produced without ANY PI request
    • PI does not charged for that
    • will be done during day time, possibly twilight and night time
  3. User request charged calibrations (UCC):
    • will be produced by PI request
    • will be done during night time
    • PI will be charged for that
  4. User requested non-charged calibrations (UNC):
    • will be produced by PI request
    • will be done during day time
    • PI will be not charged for that

 

SALT Calibration Plan for Commissioning Proposals:

  • The Performance Verification (PV) time will be used to define a set of  Default  Calibrations (DC) for the different modes of the instruments.
  • There is no need for the PI to ask for DC, they will be taken anyway.  The details of what we currently foresee the DC to contain are presented in the next section and will include at least the following: all relevant biases, arcs, calibration unit flat fields and spectroscopic standards. Whether some of these flux standards can be taken in the evening or morning twilight will be investigated during the PV phase. The exact nature of the DCs may change as we gain experience in observing and reducing the data and updates will be posted as necessary.
  • In normal operations, the PIPT will have the functionality for PIs to make up their calibrations for any special purpose.   However, this functionality will not be available during the PV phase.
  • During PV phase, if the PI really is in need of some specially designed  calibrations, they should enter these requirements in the "comments" box for the observation blocks and/or contact the SALT Operations team.
  • During PV phase, as well as normal operations, if a PI wants a specific star to be observed as a calibration standard (e.g. flux, radial velocity, telluric) star, it should be entered in the PIPT as a normal science target (UCC).

Minimal DCs for Commissioning Proposals:

SCAM imaging:

  • 11 bias frames per CCD setup
  • 3 screen flats per CCD & Camera setups

 RSS longslit:

  • 11 bias frames per CCD setup
  • five spectral screen flats per spectral setup
  • two arc lamp per setup: before and after observation
  • one spectrophotometric standard per setup