Slant-path rain attenuation at different elevation angles for tropical region

Gamma model is used to model the drop size distribution of Singapore. Specific rain attenuation is calculated using forward scattering coefficients and using ITU-R P.838-3 recommendations for vertically polarized waves at 11 GHz, 20 GHz, 30 GHz and 38 GHz at different elevation angles. Slant path attenuation is calculated using the specific rain attenuation at different elevation angles using ITU-R P.618-9 recommendations for 11 GHz, 20 GHz, 30 GHz and 38 GHz. Both the specific rain attenuation and slant-path rain attenuation are calculated at the point rainfall rate, 120.30 mm/hr, of Singapore and at a lower rainfall rate 66.54 mm/hr. The trend of slant-path rain attenuation at different elevation angles for the four frequencies is analyzed.