Multipath scattering from complex targets

Identifying interference patterns originating from particular scatterers on complex objects above an electromagnetic smooth surface can be difficult, especially if the scatterers are not dominant. The author shows the existence of an incoherent scattering space where the relative positions of the scatterers in either height or range are irrelevant and where the backscattered power is the result of an incoherent summation of the reflected fields comprising the target. The incoherent scattering space is defined as that space where the maximum multipath phase shift between the scatterers is smaller than π/2. Owing to the small relative phase shift between the scatterers within this space, the fluctuations of the reflected signal are small and a point reflector may hence substitute the complex target. The existence of the space is determined by the height of the radar antenna, the relative height of the scatterers, the range and the electromagnetic frequency