The impact of strong scintillation on space-based radar design: Clutter rejection

Electromagnetic signals that propagate through strongly disturbed regions of the ionosphere can experience angular scattering that can cause appreciable amplitude and phase scintillation and angle-of-arrival fluctuations. This paper considers the clutter rejection performance of a space-based radar subject to degradation due to signal propagation through a highly disturbed propagation channel. Pertinent characteristics of the disturbed channel and the received radar signal are discussed. The effect of scintillation on the performance of a generic pulse doppler radar that utilizes Dolph-Chebyshev weighting to reduce clutter sidelobes is investigated. The clutter rejection performance of various doppler filters is given as a function of the decorrelation time of the scintillation. It is shown that this type of clutter rejection technique, which utilizes a filter with constant sidelobes, is robust in strong scintillation.