Uniform (constant with wavelength)
Blackbody: Temperature: Kelvin
Flux: 10-16 ergs/s/cm2 (per arcsec2 for extended sources)
The total exposure time, for non-chopping mode, is the product of
DIT (Detector Integration Time) and NDIT (number of DITs). This exposure time does not take into account instrument and telescope overheads.
S/N as a function of Exposure Time
S/N as a function of seeing (only for point-source)
Input spectrum in physical units