Telescope Performance Overview

Caution: some performance characteristics have yet to be determined definitively.

• Tip-tilt image quality estimates are presented as part of the observing condition constraints. Use of wavefront sensors is assumed (see the contents list for more details).
• Pointing, tracking and guiding, offsetting and slewing performance (e.g. precision and overheads) have yet to be measured. The values presented are taken from the Science Requirements Document.
• Mirror coating - a protected silver coating offers the potential for significantly reduced emissivity in the thermal infrared and higher reflectivity at wavelengths longer than about 400nm, compared to aluminium (see reflectance graph). 
• The current primary mirror coating is silver on Gemini South and Gemini North.
• The current secondary mirror coating is silver on Gemini South and Gemini North. 
• Chopping with the secondary mirror is capable of 2-point (a.k.a square wave) chopping at an arbitrary position angle on the sky, with the following constraints:
• Chop frequency: 3Hz
• Chop amplitude (on sky): 15 arcsec
• Chop duty-cycle: 87%
• Other combinations of parameters may become possible but have not been evaluated. 

Last update June 20, 2005; Phil Puxley