A clutter cancellation method in passive radar based on MUSIC time delay estimation

When detecting the targets utilizing illuminators of opportunity, the echo targets are usually masked by the strong clutter when executing time-frequency process, thus the clutter cancellation is of great importance. A clutter cancellation approach utilizing multiple signal classification (MUSIC) time delay estimation is proposed to improve the performance degradation when the clutter has fractional time delay. In the propose method, we establishes the time delay estimation model exploiting the MUSIC algorithm. Then the estimated time delay is utilized to structure the clutter matrix and the clutter cancellation is implemented by projecting the received signal to the orthogonal subspace of clutter space. Simulations prove that the proposed method keeps good cancellation performance and weak target detection performance even if the clutter has fractional time delay.