机载雷达平面阵前视杂波距离依赖性补偿
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摘要
机载前视阵雷达下,杂波具有距离依赖性,杂波脊有明显的展宽,这会影响杂波协方差矩阵的估计,并降低杂波抑制的效果。自适应角度多普勒补偿(A~2DC)算法通过估计训练样本杂波频率特性,对杂波进行自适应补偿,从而改善杂波抑制性能。但是,当天线阵元数与积累脉冲数较少时,该算法有较明显的性能衰减。文中利用平面阵俯仰维的阵元数据信息,对估计得到的杂波频率取统计平均,增加了A~2DC算法可用样本数,使得估计的杂波频率信息更精准,杂波补偿效果更好,仿真结果证明了该算法的有效性。
The clutter is range-dependent and the clutter ridge will broaden for airborne radar,especially for forward-looking radar.Then the clutter covariance matrix( CCM) estimated by the secondary data snapshots will be inaccurate,which will degrade the performance of clutter suppression. The adaptive angle-Doppler compensation( A~2DC) estimates the clutter frequency characteristics of the training snapshots,and compensates the clutter adaptively,which will improve the clutter suppression performance.However,when the numbers of the antenna elements in the horizontal direction and pulses are few,the performance of A~2DC will degrade seriously. In this paper,we make use of the echo of the vertical elements of the planar array,and then take the average of the estimated clutter frequency before. As a result,the snapshot number used for A~2DC will increase and the estimated clutter frequency will be more accuracy,which can make a better performance in clutter compensation. The simulations verify that the modified algorithm is effective.
The clutter is range-dependent and the clutter ridge will broaden for airborne radar,especially for forward-looking radar.Then the clutter covariance matrix( CCM) estimated by the secondary data snapshots will be inaccurate,which will degrade the performance of clutter suppression. The adaptive angle-Doppler compensation( A~2DC) estimates the clutter frequency characteristics of the training snapshots,and compensates the clutter adaptively,which will improve the clutter suppression performance.However,when the numbers of the antenna elements in the horizontal direction and pulses are few,the performance of A~2DC will degrade seriously. In this paper,we make use of the echo of the vertical elements of the planar array,and then take the average of the estimated clutter frequency before. As a result,the snapshot number used for A~2DC will increase and the estimated clutter frequency will be more accuracy,which can make a better performance in clutter compensation. The simulations verify that the modified algorithm is effective.
引文
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[10]YANG Z,LI X,WANG H,et al.Knowledge-aided STAP with sparse-recovery by exploiting spatio-temporal sparsity[J].IET Signal Processing,2016,10(2):150-161.
[2]张良,徐艳国.机载预警雷达技术发展展望[J].现代雷达,2015,37(1):1-7.ZHANG Liang,XU Yanguo.Prospect for technology of airborne early warning radar[J].Modern Radar,2015,37(1):1-7.
[3]邵春生.相控阵雷达研究现状与发展趋势[J].现代雷达,2016,38(6):1-4.SHAO Chunsheng.Study status and development trend of phased array radar[J].Modern Radar,2016,38(6):1-4.
[4]LIU A,SUN H,TEH K C,et al.Robust space-time adaptive processing for nonhomogeneous clutter in the presence of model errors[J].IEEE Transactions on Aerospace&Electronic Systems,2016,52(1):155-168.
[5]KREYENKAMP O,KLEMM R.Doppler compensation in forward-looking STAP radar[J].IEE Proceedings-Radar,Sonar and Navigation,2001,148(5):253-258.
[6]BORSARI G K.Mitigating effects on STAP processing caused by an inclined array[C]//Proceedings of the 1998 IEEE Radar Conference.Dallas,TX,USA:IEEE Press,1998:135-140.
[7]HIMED B,ZHANG Y,HAJJARI A.STAP with angle-Doppler compensation for bistatic airborne radars[C]//2002 Proceedings of the IEEE Radar Conference.Long Beach,CA,USA:IEEE Press,2002:311-317.
[8]MELVIN W L,DAVIS M E.Adaptive cancellation method for geometry-induced nonstationary bistatic clutter environments[J].IEEE Transactions on Aerospace&Electronic Systems,2007,43(2):651-672.
[9]ZATMAN M,MARSHALL D.Forward-backward averaging in the presence of array manifold errors[J].IEEE Transactions on Antennas&Propagation,1998,46(11):1700-1704.
[10]YANG Z,LI X,WANG H,et al.Knowledge-aided STAP with sparse-recovery by exploiting spatio-temporal sparsity[J].IET Signal Processing,2016,10(2):150-161.