Radar Coverage Over Irregular Terrain: A Practical Algorithm for Multipath Propagation

In this paper, the impact of the multipath reflections over irregular terrain profiles on the performance of radar detection is analyzed through the prediction of detection coverage in a radar system. To this end, we propose a geometric algorithm for the search of reflection rays over real irregular terrain, which is described by the earth's curvature, shadowing regions, and the knowledge of the target positions. The reflection points are based on the difference between incident and reflected grazing angles as a function of the range parameter. The analytical formulation is given by an ordinary differential equation (ODE), which improves the solution by incorporating non-linear modeling into irregular terrain surface. The probability of detection is quantified by the Marcum-Q function for a set of targets, which is extended to contain the effect of the antenna pattern on the multipath environment for a given signal-to-noise ratio value and probability of false alarm. Figures present vertical profiles and 360 degrees coverage. The new solution reveals the strong influence of the topographic profile on the multipath phenomenon and consequently on the detection probability performance of radar system.