Composite scattering of an electrically large ship on a two-dimensional time-evolved sea surface

Abstract

A time-varying composite scattering of a moving ship on a two-dimensional non-linear sea surface is modelled with the help of the Doppler spectrum in high-frequency bands. A non-linear sea surface is simulated to approximate a real sea environment with high-order terms of the solution to hydrodynamic equations. Numerical simulations are based on the principle of a quasi-stationary algorithm (QSA), which solves time domain problems with frequency domain methods. A four-path model is modified to calculate the composite scattering field, which is utilized for the analysis of the Doppler spectrum. With depth-buffer technology, self-shadowing of the complex physical model is eliminated. Correspondence of the numerical results with experimental data proves that the inclusion of the non-linear interaction term and wind-speed influence is reasonable. The simulated Doppler spectrum of the composite scattering shows a functional dependence of time-evolved scattering components on incidence direction and sea state.

Acknowledgements

The authors thank the Fundamental Research Funds for the Central Universities, by the National Nature Science Foundation of China under Grant No.60871070, and by the Foundation of National Key Laboratory of Electromagnetic Environmental Research to support this kind of research.