A Study on the Change of Atmospheric Duct During Cold Front Advance and its Influence on AIS Signal Propagation
The distribution of meteorological elements such as temperature,relative humidity and wind speed in the sea area will be significantly change during the advance of the cold front,the types and distribution of atmospheric duct closely related to meteoro-logical elements will be changed.In this paper,the atmospheric reanalysis data are used to analyze the change process of atmos-pheric duct in different stages during the advance of a cold front in mid-March 2018,and the influence of atmospheric duct on AIS propagation in the process of cold front advance is studied by using electromagnetic wave propagation model.The results show that the evaporation duct in the beginning and development stage of cold front has a weak influence on AIS propagation;At the exten-sion and end of the cold front,the emergence of different types of atmospheric duct has a strong impact on the propagation of AIS.Therefore,to effectively monitor the status of ships in the sea area,supplementary monitoring measures for the beginning and de-velopment stage of the cold front should be added.