The first-order bistatic high frequency radar scattering cross section of the ocean surface for the case of a floating platform

The first-order bistatic high frequency radar cross section of ocean surface is derived for the case of a fixed receiver and a floating, but tethered, transmitter. A general expression for the bistatically received first-order electric field is obtained from earlier work based on fixed antennas. A small displacement caused by the platform motion is included in the source term to modify the fixed-antenna model. Based on the assumption that the ocean surface can be described as a Fourier series with coefficients being random variables, the first-order bistatic radar cross section is derived. The cross section model is found to contain a sum of Bessel functions, varying in order from zero to infinity. Simulation results depict the effect of platform motion in the Doppler spectrum. It is shown that the location of the motion-induced peaks are symmetrically distributed in the spectrum and the magnitude decreases with increasing order of the Bessel functions. These peaks caused by the swaying motion of the transmitter platform are seen to have less energy in the bistatic cross section than those in the monostatic case.