High-Frequency Radar Cross Section of the Ocean Surface for an FMCW Waveform

The first- and second-order monostatic cross sections of the ocean surface in the context of high-frequency ground wave radar operation are derived for a dipole source with a linear frequency-modulated continuous waveform. The Fourier coefficients of the rough ocean surface are described as zero-mean Gaussian random variables. The electric field equations for the reception of vertically polarized radiation scattered from the ocean surface are obtained. The range spectra are calculated by Fourier transforming the received signal within the sweep interval. Fourier transformation of the autocorrelations of the electric fields received from the time-varying surface gives the Doppler spectra (power spectral densities). The cross sections are obtained by direct comparison of the spectral results with the monostatic radar range equation.