Research On Electromagnetic Scattering Characteristics Of Underwater Moving Body Wake

The research on the electromagnetic scattering characteristics of underwater moving body surface wake has found extensive applications in ocean remote sensing,target detection and target parameter inversion etc.The electromagnetic scattering calculation method and scattering echo characteristic of underwater moving body wake on the background of rough sea surface have been researched in this paper.It is the fundamental research work of the submarine electromagnetic detection and has important practical significance.1.The basic theory of sea geometric modeling has been introduced.Based on the analysis of several typical wave spectrum characteristics,the sea surface models are established by using Monte Carlo method and Creamer method,respectively.From the view of hydrodynamics,the mechanism of underwater moving body's water dynamic wake is analyzed and the geometry model of the Kelvin wake,narrow V wake and internal wave wake are built.In consideration of realistic sea states,the principle of conservation of wave action is used to analyze the interaction between wake and sea surface,and the composite sea model is obtained.2.In order to analyze the single scattering surface conveniently,facet-based Kirchhoff approximation(FBKA)is used to calculate the electromagnetic scattering of surface wake.The algorithm can analyze the influence of underwater moving body wakes on electromagnetic scattering from sea surface element perspectives.In the calculation,the cone wave is chosen as the incident wave in order to eliminate the edge truncation effect.Considering the shadowing effect of grazing incidence,the shadowing correction function is added to the calculation.The polarization characteristics are added to analyze scattering echo,so that the detection probability of wake target will be improved.In the process of calculation,considering the differences of salinity and temperature between the wake zone and non wake area,the effects of temperature and salinity on the electromagnetic scattering in wake region are analyzed in this paper.3.Based on the above model,numerical simulations are carried out and the results are analyzed.In the process of numerical simulation,the effects of electromagnetic scattering caused by wind direction,sea states,incident angle,movement velocity,depth,temperature and salinity are calculated.According to the results of numerical simulation,the variation regularity of electromagnetic scattering of the moving body wake is summarized in this paper.