A combined sea clutter and noise model appropriate to the operation of high‐frequency pulsed Doppler radar in regions constrained by external noise

Abstract

In recent years, bistatic pulsed high‐frequency ground wave radar models of the ocean clutter have been developed. Several new features, distinct from earlier monostatic developments, appear as products of those analyses. One question that needs to be addressed is, “What characteristics of the theoretical clutter models are likely to be visible in experimental data collected from the ocean surface?” A major consideration in answering this question is the development of an appropriate noise model. Such a model along with an analogous clutter model is derived. This allows a simulation of time series data for both clutter and noise which may be treated using standard Fourier transform techniques to provide a periodogram for the typical combined noise/clutter spectrum of scattering from the ocean surface. The analysis proceeds on the assumption of an externally noise‐limited system, with the noise being characterized as a white Gaussian zero‐mean process. The aliasing due to noise undersampling is seen to be an integral part of the model. Statistical stationarity is assumed throughout. Both infinite and finite pulse trains are considered.