Telescopes

• Telescope Pupil imaging: This system check monitors the health of the telescope mirrors and should be performed on a monthly basis. At GN the images will be taken with NIRI in the L-band (3.8 microns), and at GS the observations will be taken with T-ReCS. The observations need to be taken on the sky, preferably with no clouds (CC50), low to moderate water vapour (WV80), and unconstrained seeing (IQany).

   

• Telescope Emissivity: Monthly measurement of the telescope emissivity will be made using NIRI at GN and T-ReCS at GS. The NIRI observations include Br(alpha) (4.05 microns) and Lprime (3.78 microns) images of the sky at zenith and elevation = 30 degrees (2 airmasses). The observations need to be taken with no clouds (CC50), low to moderate WV (WV80), and unconstrained seeing (IQany).