Change page style:
The optical elements of GMOS (e.g. filters, gratings and slits) are described in detail on the main GMOS pages.
The observing condition constraints define the poorest conditions under which a queue-scheduled observation should be executed and indicate the conditions that can be expected by classically-scheduled observers. See the detailed translation between frequency of occurrence (the %-ile bin) and physical property, which is a function of observing wavelength and zenith distance of the source.
This page describes some telescope properties relevant to ITC calculations. See the Gemini telescope pages for more details.
The Gemini coating chamber is capable of depositing either alumini(u)m or silver. Currently the primary, secondary and tertiary (science fold) mirrors on both telescopes are silver coated. This graph shows the reflectivity of Al and Ag.
The optical elements of NIRI (e.g. cameras, filters, grisms and slits) are described in detail on the NIRI pages.
The filter menu is divided into broad- and narrow-band filters, in order of increasing wavelength. For spectroscopy, select the "grism order sorting" filter from the menu, the appropriate grism (disperser) and slit.
The ability of the AO system to correct the wavefront depends on the brightness and off-axis angle of the wavefront reference source (the AO "guide star"). The Strehl ratio of the AO-corrected core is approximated in the ITC by:
Changes included in the v2.0 releases (issued 8 March 2002) are listed below.
Changes and bugs (coded red, or black if fixed) within the Integration Time Calculator are listed below. See the main ITC page for a list of the most recent changes.
There are two modes available:
- Calculate the total signal-to-noise ratio (S/N) for an observation with the specified exposure time, number of exposures and sky subtraction method
- Calculate the total integration time to achieve the requested S/N for an observation with the specified exposure time and sky subtraction method