A High-Frequency Surface Wave Radar Ionospheric Clutter Model for Mixed-Path Propagation With the Second-Order Sea Scattering

A theoretical second-order monostatic high-frequency radar power model is derived for the case of mixed-path ionosphere-ocean propagation. First, the general form of the received electric field is investigated by considering the ionospheric reflection and the second-order sea scattering, which involves both electromagnetic and hydrodynamic contributions. Then, this field is inversely Fourier transformed to the time domain, and a pulsed source is incorporated. Subsequently, the second-order received power model is developed by assuming that the ionospheric reflection coefficient and the ocean surface can be described as Fourier series whose coefficients are random variables. In order to investigate the power spectrum of the mixed-path propagation and its relative intensity to that of the surface propagation under a variety of ionospheric conditions and sea states, a normalized power is simulated.