Numerical study of microwave backscattering from time-evolving JONSWAP-type mixed ocean waves

ABSTRACT

The microwave backscattering from mixed wind-driven wave and swell marine environment is important for estimation of sea state, ship responses analysis, etc. However, most studies mainly focus on the wind wave only. It has been found that the JONSWAP spectrum is suitable for describing not only wind wave but also swell. The Doppler spectrum of dynamic JONSWAP-type nonlinear waves is used as a tool to analyse the microwave backscattering features of mixed ocean waves. The Doppler central frequency and Doppler bandwidth of mixed sea are calculated by the second-order small-slope approximation theory (SSA-II), and the numerical simulation results indicate that the swell impacts Doppler features mainly at small incident angles and the corresponding results are nearly insensitive to polarization, whereas the wind wave relatively dominates the microwave backscattering from mixed sea.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant Nos. 41306188 and 61372004, the Natural Science Basic Research Plan in Shaanxi Province of China (No. 2016JQ6055), Shanghai Aerospace Science and Technology Innovation Fund (SAST2015008), and the China Postdoctoral Science Foundation (No. 2015M572524).