Degradation of ground-based RADAR performance due to vegetation cover

Several studies indicate that vegetation attenuates and scatters radio waves. Although researchers considered vegetation as a soft obstacle in terms of total attenuation, actual measurements show that trees or shrubs could induce important attenuations. This opens a possible use when looking for radar invisibility shields to protect selected targets. Is it possible to use vegetation as an invisibility cover? If so, under which conditions this procedure would work? These are the questions this paper tries to answer, analysing the degradation in the probability of detection that a vegetation cover induces in the radar system. We present the results from large measurement campaigns on attenuation due to vegetation, performed at radar UHF and microwave frequencies; then we use them to evaluate the reduction in the radar performance when trying to detect a target protected by a vegetation cover. We demonstrate that vegetation covers lead to reductions in probability of detection to values below 0.1 considering single pulse radars, which means that the target would be undetectable. We conclude that the proposal would be reliable, even taking into account other additional effects, as pulse integration, the natural time variability of the induced attenuation, and the noise increase due to the vegetation scattering.