def signal_to_noise_oir_ccd(t, source_eps, sky_eps, dark_eps, rd, npix, gain=1.0):
 signal = ((t * source_eps) * gain)
 noise = np.sqrt(((t * ((source_eps * gain) + (npix * ((sky_eps * gain) + dark_eps)))) + (npix * (rd ** 2))))
 return (signal / noise)

def signal_to_noise_oir_ccd ( t , source_eps , sky_eps , dark_eps , rd , npix , gain = 1.0 ) : signal = ( ( t * source_eps ) * gain ) noise = np . sqrt ( ( ( t * ( ( source_eps * gain ) + ( npix * ( ( sky_eps * gain ) + dark_eps ) ) ) ) + ( npix * ( rd ** 2 ) ) ) ) return ( signal / noise )
computes the signal to noise ratio for source being observed in the optical/ir using a ccd .