Only in the presence of sidelobe jamming （SLJ）, can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously. While mainlobe jamm...Only in the presence of sidelobe jamming （SLJ）, can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously. While mainlobe jamming （MLJ） exists, the mainlobe of adaptive pattern will subject to serious distortion, which results in a failure of detecting and tracking targets by monopulse technique. Therefore, a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented. This algorithm utilizes both high gain difference beams and high gain auxiliary beams for cancelling the mainlobe jammer and multiple sidelobe jammers （SLJs） while keeping an adap- tive monopulse ratio. Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well, which improves the monopulse angle accuracy greatly. Furthermore, the proposed algorithm is of simple implementation and low computational complexity.展开更多
This paper analyzes the characteristics of ionospheric clutter, which has proven to be the greatest impediment in high frequency surface wave radar （HFSWR）. Ionospheric clutter influences most range bins, all Dopple...This paper analyzes the characteristics of ionospheric clutter, which has proven to be the greatest impediment in high frequency surface wave radar （HFSWR）. Ionospheric clutter influences most range bins, all Doppler bins and beams, and exhibits a high directivity. A robust adaptive side-lobe cancellation algorithm based on orthogonal auxiliary beams, which use the difference beams to estimate the ionospheric clutter information, is introduced to suppress the ionospheric clutter. Training data was selected by excluding the sea clutter and probable target unit; and diagonal loading was added to enhance the robustness of the algorithm. Experimental results demonstrate that the algorithm is able to suppress the ionospheric clutter whilst preserving the desired characteristics of the target echoes and is suitable for practical implementation.展开更多
基金supported by the National Natural Science Foundation of China(60925005)
文摘Only in the presence of sidelobe jamming （SLJ）, can the conventional adaptive monopulse technique null the jamming effectively and maintain the monopulse angle estimation accuracy simultaneously. While mainlobe jamming （MLJ） exists, the mainlobe of adaptive pattern will subject to serious distortion, which results in a failure of detecting and tracking targets by monopulse technique. Therefore, a monopulse angle estimation algorithm based on combining sum-difference beam and auxiliary beam is presented. This algorithm utilizes both high gain difference beams and high gain auxiliary beams for cancelling the mainlobe jammer and multiple sidelobe jammers （SLJs） while keeping an adap- tive monopulse ratio. Theoretical analysis and simulation results indicate that the serious invalidation of monopulse technique in MLJ and SLJs scenarios is resolved well, which improves the monopulse angle accuracy greatly. Furthermore, the proposed algorithm is of simple implementation and low computational complexity.
文摘This paper analyzes the characteristics of ionospheric clutter, which has proven to be the greatest impediment in high frequency surface wave radar （HFSWR）. Ionospheric clutter influences most range bins, all Doppler bins and beams, and exhibits a high directivity. A robust adaptive side-lobe cancellation algorithm based on orthogonal auxiliary beams, which use the difference beams to estimate the ionospheric clutter information, is introduced to suppress the ionospheric clutter. Training data was selected by excluding the sea clutter and probable target unit; and diagonal loading was added to enhance the robustness of the algorithm. Experimental results demonstrate that the algorithm is able to suppress the ionospheric clutter whilst preserving the desired characteristics of the target echoes and is suitable for practical implementation.
