Doppler Return from a Random Rough Surface

A theoretical analysis of the Doppler return from a random rough surface ace shows that the Doppler spectrum is composed of three distinct components. The methods of analysis for determining the average power return for the static case and an application of the ergodic hypothesis for a stationary surface show that the assumption of a single Doppler component is based on a smooth surface. In addition to this coherent component, the incoherent components of the random rough surface produce two additional frequency components. The amplitudes of these latter components depend on the variance of the surfaceand the antenna beamwidth averaging. Radar measurements were made, utilizing a scatterometer, in order to measure the surface characteristics. s. Simultaneous measurements from a Doppler radar system were analysed to identify the additional frequency components.