Analysis of ducting effects on air-to-ground propagation channel over sea surface at C-band

This paper reports a further investigation into the ducting effects (evaporation duct and elevated duct) on air-to-ground over-sea radio-wave propagations at C-band (5.7 GHz) with airborne altitudes of 0.37-1.83 km. In this study, the measured propagation loss is used to estimate the possible signal enhancement due to ducting effects. Statistical analysis of the signal enhancement is carried out, and the results are found to be Gaussian distributed. The observations from the measurements results show that the evaporation duct and the elevated duct over the sea surface are important effects that can significantly improve the over-sea air-to-ground radio-wave propagation.