Application of Ray Tracing for Beyond-line-of-sight Maritime Communication in Evaporation Ducts

Atmospheric ducts provide a potential way to establish beyond-line-of-sight (B-LoS) links for maritime communications. Based on the ray tracing (RT) method, long distance propagation in the maritime evaporation duct environment is studied in this paper. The variations of horizontal distance and height are calculated according to the refractivity distribution. Eigenrays between transmitter (Tx) and receiver (Rx) are determined by tracing the ray trajectories. Furthermore, the path loss, delay spread, and angles of arrival (AoAs) are estimated. Simulation results calculated by the RT method match theoretical results generated by parabolic equation (PE) methods in the short range. In the B-LoS range, the path loss estimated by RT is a bit higher than that estimated by PE. In the RT model, the increase in the number of rays calculated in the B-LoS range may lead to this case. Simulation results show that the RT method can well evaluate the anomalous propagation in the evaporation duct and estimate channel parameters effectively.