The NIRI beam-splitter wheel contains three beam-splitters to direct the science beam and OIWFS (On-instrument wavefront sensor) beam to the appropriate on-board instruments. The beam-splitters are flat mirrors of different sizes to allow the OIWFS beam for each camera, f/6, f/14 and f/32, to be picked off without modifying the science
On Gemini, science instruments are mounted at the cassegrain focus below the 8.2 meter primary mirror. The picture below shows a schematic of the telescope and specifically the bottom end where instruments are mounted. The f/16 telescope beam passes through the 1.18 meter diameter central primary hole, through the Acquisition &
The Observing Tool libraries contain "pieces" of observations e.g. commonly used configurations, sequences, standard calibrations and ancillary information which may be copy-and-pasted into a new observation. The intent of these libraries is to speed the development of new science programs. As observing procedures and instrumental configurations may change from semester to semester (installation of new GCAL filters, for instance), it is advisable that PIs download the most recent libraries when defining new observations.
Progress is being made at the University of Florida towards preparing T-ReCS for pre-ship acceptance tests prior to its delivery to Gemini. Although substantially improved, issues remain with flexure and elevated system noise. In addition, several key measurements such as the internal cryostat background and characterisation of the science-grade detector have yet to be carried out.