Channel Measurement and Spatial Characteristics Analysis of mmWave Propagation in Maritime Evaporation Ducts

This paper analyzes the channel characteristics and spatial propagation characteristics of millimeter waves in evaporation ducts on the sea surface through field measurements. Research has found that there is a clear correlation between the power level of the received signal and the horizontal and vertical receiving angles. The experiment used USRP X310 to analyze the received power of signals at different antenna angles, and calculated the average and standard deviation of the received power. The results indicate that beam alignment in the horizontal direction is beneficial for high-quality signal reception, while signal power decreases significantly when the horizontal direction deviates by a large angle. In addition, the decreasing trend of received power with the change of vertical angle slows down significantly, and even at an elevation angle of 60°, signals can still be higher than noise threshold, which further confirms the vertical multipath effect in the evaporation ducts.