New Methodology for Predicting Vertical Atmospheric Profile and Propagation Parameters in Subtropical Arabian Gulf Region

A new simplified approach is proposed to evaluate the vertical refractivity profile within the lowest 1 km of atmosphere from the analysis of surface refractivity N8 in areas where upper-air data are not available. Upper-air measurements from the nearest available radiosonde location with similar surface profile to these sites are utilized. The profiles of N8 and refractivity extrapolated to sea level No obtained from surface meteorological data using both fixed stations and radiosonde are investigated and compared. Vertical refractivity gradient ΔN is evaluated at three atmospheric layer heights within the first kilometer above the ground in addition to propagation parameters relevant to each atmospheric layer. At six sites, different approaches are compared for the analysis of three important parameters; namely effective earth radius factor k anomalous propagation probability parameter β
_ο
and point refractivity gradient at 65 m not exceeded for 1% of time dN
₁
. The k-factor parameter is investigated using a new weighted average approach of ΔN at 65-m, 100-m, and 1-km layers above the ground. The results are compared with the latest ITU maps and tables for the same area.