Modification of Earth-Space Rain Attenuation Model for EarthSpace Link

Abstract

Rain attenuation is the primary source of signal degradation especially for those operating at frequencies up to 10 GHz. Achieving precise prediction of the rain attenuation to certain location is quite difficult due to the inhomogeneity of the rain along the propagation path. Vertical and horizontal reduction factors playing a significant role to estimate the effective path length precisely by reducing the actual path length penetrated in the rain. This paper presents the rain attenuation prediction based on the knowledge of rain microstructure parameters such as the raindrop size, rainfall rate and the raindrops size distribution. The drop size distribution is calculated based on Marshall-Palmer model. The total link attenuation has been calculated using the modified model proposed in (1) to find the total effective path attenuation of HAPS earth- space link located in Kuantan Malaysia (3.80°N, 103.32°E). The frequency of the predicted signal has been carried out in this study is 31 GHz, while the polarization which used is circular polarization. Keywords: HAPS; rain attenuation; rain prediction mode; Ka-band fade; rain cell size attenuation.