Random range sidelobes analysis and suppression in airborne passive radar

The severe interference environment in an airborne passive radar is usually characterized by the high levels of direct path and clutter signals against the thermal noise background. Owing to the properties of the passive signal, the random range sidelobes of the direct path and of the strong clutter will exhibit significant couplings into further range cells. The random range sidelobes of the strong clutter may cause moving target detections to be random range sidelobes limited. An adaptive interference cancellation technique is proposed to suppress these interfering signals received at each antenna element. Simulations showed that the algorithm is effective in suppressing the undesirable direct path and strong clutter signals which in turn reduces their corresponding random range sidelobes coupling effects that manifest into further range cells, lowering the overall pedestal in the ambiguity function and spatial-Doppler power spectrum. (5 pages)