Study on Wireless Detection in Condition of Evaporation Duct

Evaporation duct is a layer of air just above the sea surface which can trap wireless energy. It is created by the rapid decrease of humidity with height just above the sea surface. Owing to it, the path of wireless wave is changed remarkably, the wireless detection range will be increased to realize the phenomenon of OTH (over-the-horizon) detection, so it is very important in wireless detection over the ocean. This paper uses actual evaporation duct height data measured in recent years to choose better one of two widely used evaporation duct models in sea areas, and the better model is applied to PEM (parabolic equation method) as input to calculate wireless detection range. The wireless detection experiment result presented in this paper describes that actual wireless detection range coincides with the prediction result based on evaporation duct model and PEM.