Detection of noctilucent clouds in the twilight layer from satellites

The possibility of detecting noctilucent clouds against the background of the sky has been discussed recently by Deirmendjian [1963] and by Rosenberg [1966]. Twilight contrast [Rosenberg, 1966]. The treatment adopted by Rosenberg is based on tracing a beam of radiation throughout its path to the observer in a spherical conservative Rayleigh atmosphere in which refraction is neglected.