Signal-to-Noise Calculator

k is the magnitude zero point. ADUs are computed using the GRIM II (mid-90s) value of 4.73 e-/ADU.


object size (pixels)
readout noise (e-/pixel)
k (phot/s/cm/cm/Å)
object magnitude
sky brightness (mag/arcsec2)
filter bandwidth (Å)
pixel area (arcsec2)
system efficiency
ND# (e-/phot)
telescope area (cm2)