Scaling Cloud Attenuation Statistics With Link Elevation in Earth-Space Applications

A methodology to scale cloud attenuation statistics with link elevation in Earth-space applications is presented in this contribution. The vertical and horizontal distribution of clouds is investigated by taking advantage of the liquid water content observed by the cloud profiling radar (CPR) onboard the CloudSat Earth Observation satellite. Besides casting some light on the actual validity of the customary assumption of horizontal uniformity for clouds, analytical expressions for the scaling factor are proposed to derive cloud attenuation statistics on slant paths from attenuation predictions at zenith. The proposed methodology could be beneficial to improve the accuracy of the model currently adopted by the ITU-R in recommendation P.840-6, especially when low elevation links (e.g., between 5° and 20°) are involved.