Scattering and Doppler analysis for electrically large nonlinear sea surfaces: a field-based semi-deterministic model

ABSTRACT

This paper presents a semi-deterministic facet model based on the combination of the two-scale theory and the small slope approximation (SSA). Based on the model, normalized radar cross section (NRCS) and the Doppler spectra from electrically large nonlinear ocean scenes are analysed at moderate and large incidence angles. The analytic scattering amplitude of small-scale capillary waves based on the local configuration angles is conducted. Different from the conventional two-scale model (TSM), the model is a field-based rather than RCS-based model, which considerably widens its potential applications. In order to take into account the influence of nonlinear hydrodynamics on echo characteristics, the choppy wave model (CWM) is adopted to simulate nonlinear surfaces. Several examples of bistatic NRCS and Doppler spectra are given with comparison and analysis, which validate the rationality of the model at moderate and large incidence angles. In addition, the running time and memory consumption comparisons can indicate the model is more efficient than the SSA.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by National Nature Science Foundation of China [grant number 61372004].