Time-domain clutter model for airborne pulse Doppler radar

The calculation of surface clutter returns to an airborne radar is complicated. Detailed clutter models have been developed for the study of surface scattering and the characterisation of clutter returns. In look-down air-to-air radar operation the general strategy is to detect targets which can be separated from clutter. In a statistical analysis of this detection process, an increase in the speed of calculation is desirable, hence simplified clutter models are used-often performing the calculations in the frequency domain, after Fourier processing. This approach, however, is often restricted by geometry and does not allow simulation of the entire detection process undergone in a radar. The availability of extremely fast desktop workstations in the last few years has allowed computational models to be based on enormous numbers of calculations performed in relatively short times. Consequently approximations and complex theory can now be displaced by mathematical models which are theoretically simple but computationally intensive. In this paper we introduce such a model. The clutter returns are generated over the entire surface area intersected with the radar antenna pattern, and the accumulated signal calculated in a piecewise linear fashion. No symmetrical arguments are introduced to reduce the computation hence the model is not restricted by geometry. The clutter model simulates a time-domain signal, which is equivalent to that output by the receiver and input to the start of the signal processing chain.