Interference Suppression for Ship-Based Passive Synthetic Impulse and Aperture Radar

Interference statistic characteristic is theoretically analyzed in ship-based passive synthetic impulse and aperture radar (SIAR) scenario. Covariance matrix at interested range bin is estimated using echoes from some positive and all negative frequency range bins after stretching with cosine weight for co-channel interference suppression. Thereafter, Karhunen-Loeve transformation is applied to the echo received for co-channel interference suppression provided that its power is stronger than radar echoes. Meanwhile, the suppression approach of nonstationary interference owing to multipath propagation is proposed whereby fast-time STAP updated for PRI to PRI, while the slow-time statistical properties of first order sea clutter output are unaffected by fast-time STAP fluctuation. Effectiveness of interference suppression is confirmed by real data