HIRES Exposure Time Calculator
Computing S/N ratio for compact source
version 2.0
Program description
Main Input Parameters
λ (μm)
[0.35-2.5]
Exposure Time (sec)
NDIT
(number of separate read outs to reach the exposure time)
Magnitude (AB units)
R
Diameter of spectrograph aperture (arcsec on sky)
(use -1 for default values)
Other Input Parameters
Instrument Efficiency
Telescope Efficiency
(use -1 for values released by ESO)
Airmass
Sky Background (AB mag/arcsec
2
)
(use -1 for default values)
Telescope and optics temperature (K)
Telescope and optics emissivity
Telescope Diamater (m)
Central obscuration fractional diameter
Slit efficiency
(fraction of object-light falling in the spectrometer aperture: use -1 for values released by ESO)
Pixel size (μm)
Focal aperture of camera
On-chip binning
(total number of pixels, only for λ <0.95 μ m)
Detector Read Out Noise (e
-
/px)
Detector Dark Current [e
-
/px/hr]