The airborne conformai array (CFA) radar's clutter ridges are range-modulated, which result in a bias in the estimation of the clutter covariance matrix (CCM) of the cell under test (CUT), further, reducing the clutter suppression performance of the airborne CFA radar. The clutter ridges can be effectively compensated by the space-time separation interpolation (STS-INT) method, which costs less computation than the space-time interpolation (STINT) method, but the performance of interpolation algorithms is seriously affected by the short-range clutter, especially near the platform height. Location distributions of CFA are free, which yields serious impact that range spaces of steering vector matrices are non-orthogonal complement and even no longer disjoint. Further, a new method is proposed that the short-range clutter is pre-processed by oblique projection with the intersected range spaces (OPIRS), and then clutter data after being pre-processed are compensated to the desired range bin through the STSINT method. The OPIRS also has good compatibility and can be used in combination with many existing methods. At the same time, oblique projectors of OPIRS can be obtained in advance, so the proposed method has almost the same computational load as the traditional compensation method. In addition, the proposed method can perform well when the channel error exists. Computer simulation results verify the effectiveness of the proposed method.

中文翻译：

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机载CFA雷达结合斜投影和插值的短程杂波抑制方法

机载共形阵列（CFA）雷达的杂波脊是经过距离调制的，这会导致被测单元（CUT）的杂波协方差矩阵（CCM）的估计存在偏差，进而降低了机载杂波抑制性能CFA雷达。时空分离插值（STS-INT）方法可以有效地补偿杂波脊，与空时插值（STINT）方法相比，此方法所需的计算量更少，但内插算法的性能会受到短距离的严重影响杂乱无章，尤其是在平台高度附近。CFA的位置分布是自由的，这会产生严重影响，使转向矢量矩阵的范围空间成为非正交补码，甚至不再相交。进一步，提出了一种新的方法，即利用相交的距离空间（OPIRS）通过倾斜投影对短程杂波进行预处理，然后通过STSINT方法将预处理后的杂波数据补偿到所需的距离档。OPIRS还具有良好的兼容性，可以与许多现有方法结合使用。同时，由于可以预先获得OPIRS的斜投影仪，因此该方法的计算量与传统补偿方法几乎相同。另外，在存在信道错误的情况下，该方法可以很好地执行。计算机仿真结果验证了该方法的有效性。OPIRS还具有良好的兼容性，可以与许多现有方法结合使用。同时，由于可以预先获得OPIRS的斜投影仪，因此该方法的计算量与传统补偿方法几乎相同。另外，在存在信道错误的情况下，该方法可以很好地执行。计算机仿真结果验证了该方法的有效性。OPIRS还具有良好的兼容性，可以与许多现有方法结合使用。同时，由于可以预先获得OPIRS的斜投影仪，因此该方法的计算量与传统补偿方法几乎相同。另外，在存在信道错误的情况下，所提出的方法可以很好地执行。计算机仿真结果验证了该方法的有效性。