The following keys are used to define a SCIENCE VISIR setup:
spectroscopy:ins.slit1.wid, ins.grat1.wlen, ins.filt2.name
The following checks are performed:
imaging standard stars should be taken within +/- 2 hr from the science observations
telluric standard stars should be taken within +/- 2 hr and within the airmass difference of 0.2 from the science observation.