GNIRS has many possible configurations. They can be grouped into seven basic spectroscopic modes:

• Long slit, 0.9-2.5 µm, R>5000 (low background): R=5900 and 18000
• Long slit, 1.1-2.5um, R<5000 (OH limited): R=1700; wavelengths < 1.15 µm not recommended
• Long slit, 2.9-5.5um, all resolutions (high thermal background): R=1700, 5900 and 18000
• Cross-dispersed, 0.9-2.5 µm simultaneous: R=1700 and 5900 (partial coverage)
• IFU (no longer offered), 0.9-2.5 µm (low background): R=1700 and 5900
• IFU (no longer offered), 2.5-5.5 µm (high background): not fully commissioned, please inquire if interested

See the GNIRS gratings page for full details of operational constraints such as order overlap. The only imaging modes of GNIRS are for target acquisition and pupil viewing.