Statistical Characterization of Surface Duct Conditions and their Implications on Microwave Propagation Over Lagos, Nigeria

Abstract

Surface ducts, and atmospheric layers that trap and guide radio waves can significantly impact microwave signal propagation. Consequently, in this study, we analyzed their statistical occurrence in Lagos, Nigeria, using five years (2018-2022) of meteorological data from the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-5 reanalysis. The investigation focused on how factors like temperature, humidity, and pressure influence radio refractivity and the formation of surface ducts at different heights (100 m and 300 m) and observation times (00:00 and 12:00 hours). The results reveal a higher prevalence of surface ducts at 100 meters, particularly during the dry season (November-March) and at noon (12:00 hour). This implies that microwave signals are more likely to be trapped and travel farther during these periods, potentially causing interference with distant communication systems. Our findings establish the importance of considering surface ducts when designing and deploying communication infrastructure in coastal regions like Lagos.