Feasibility Analysis of Using Evaporation Duct for Communication in the South China Sea

Evaporation duct is a phenomenon that almost always exists across the global oceans, facilitating electromagnetic waves to propagate beyond the horizon and enabling over-the-horizon communication. This paper presents a simulation-based analysis of the feasibility of utilizing evaporation duct for communication in the South China Sea. Initially, atmospheric refractivity profiles and evaporation duct heights were derived from meteorological observation data obtained from gradient towers in the South China Sea. Subsequently, the parabolic equation (PE) model was employed to simulate the propagation characteristics of electromagnetic waves under these specific evaporation duct conditions. This simulation provided insights into the variation of propagation losses with distance and transmission frequency, ultimately identifying the optimal communication frequency for achieving long-range communication. Furthermore, a simulation of the communication link system was conducted, with the receiver's signal-to-noise ratio (SNR) being assessed across different time periods. The feasibility of using the evaporation duct for communication was analyzed. The results indicate that under these evaporation duct conditions, 89.58 percent of SNR surpassed the threshold of 40 dB, indicating the potential for effective communication.