CRIRES User Manual
Doc. Number: ESO-254264
Doc. Version: P109.4
Issued on:
2021-12-01
Page:
79 of 99
Document Classification: ESO Internal Use [Confidential for Non-ESO Staff]
7. REFERENCE MATERIAL
7.1 Calibration Plan
The calibration plan defines the default calibrations obtained and archived for the user by
the Paranal Science Operations. The CRIRES science calibration plan currently includes
the following measurements. Note that ESO reserves the right to decrease the calibration
frequency if tests show that this has no effect on the quality of the reduced data.
All standard calibrations will be acquired by the Observatory staff during the day following
the night of the observations (or within the validity period indicated in the tables below).
"Matching parameters" describes the most critical parameter for generating the automatic
calibration. For instance, darks will have the same DIT as the science frames, flats will be
taken in the same wavelength setup as the science, etc.;; wavelength calibrations and flat
field exposures will be taken through the 0.2” or 0.4” slit.
In the YJHKL bands, the daily calibrations are always taken with metrology.
Table
17
lists the regular standard calibration typically taken in the morning after the observations,
which
Table
18
shows the long-term calibrations for instrument stability monitoring.
Table 17: Standard calibrations
Calibration
Number
Matching parameters
Validity
Darks for staring mode
3
wavelength, DIT
1 day
Flats
3
wavelength, slit width
1 day
Wavelength YJHK (FP etalon)
1
wavelength, slit width
1 day
Wavelength YJHK (UNe lamp)
1
wavelength, slit width
1 day
Wavelength LM (N
2
O gas cell)
1
wavelength, slit width
1 day
SGC spectrum for data taken
with the SGC
1
wavelength, slit width
1 day
Table 18: Instrument monitoring calibrations and long-term calibrations
Calibration
Purpose
Frequency
Spectral resolution (day)
Monitoring of the spectral resolving power
2 / week
RV standard stars (night)
Monitoring of radial velocity stability
1 / week
Efficiency monitoring (night) Throughput monitoring with standards
1 / 30 days
Deep Flats (day)
Provide high S/N flats in the YJHKL bands
to the exoplanet community
1 / 90 days
Polarimetric
calibrations
(day)
Monitoring of the polarimeter with the FP
etalon
1 / 180
days