Abstract: The clutter distribution of airborne radar with non-sidelooking array antennas varies with ranges and samples in different range gates are not independent identically distributed vectors, so that the statistical Space Time Adaptive Processing（STAP） methods degrade. Traditional Doppler Warping（DW） method does compensation only in the mainlobe direction and there is still large clutter dispersion in the directions of sidelobe, so it can only alleviate the clutter nonhomogeneity in some degree. An improved clutter suppression method for non-sidelooking airborne radar, namely Modified Doppler Warping（MDW） method, is proposed. This improved method involves in a preprocessing with DW method to bring clutter spectrum of different range gates together in the mainlobe and subsequently clutter compensation to accomplish space angle of different range gates alignment at multiple Doppler bins. Simulation results show, compared with Doppler warping algorithm, the proposed method can further reduce the clutter nonhomogeneity of non-sidelooking array and performs significantly better than DW algorithm while the computation load is almost equivalent to it.

Key words: non-sidelooking array, airborne radar, Doppler Warping（DW）, clutter suppression, Space-Time Adaptive Processing（STAP）

摘要： 非正侧机载雷达的杂波分布随距离变化而变化，各距离单元的杂波分布不再满足独立同分布条件，导致统计型STAP处理器性能下降。多普勒频移（Doppler Warping，DW）算法沿主波束方向对杂波非均匀进行了补偿，但在其余方向上杂波非均匀依然存在，因而性能较差。提出了一种改进的非正侧视机载雷达杂波抑制算法——修正的多普勒频移法（Modified Doppler Warping，MDW），先通过多普勒频移法使各距离单元的杂波谱在主波束方向重合，再沿多个多普勒通道使参考单元和检测单元的杂波谱保持一致，进一步消除非正侧视机载雷达的杂波非均匀程度。仿真结果表明，与原有方法相比，该方法的杂波抑制性能有明显提高，且运算量增加不多，是一种具有工程应用价值的方法。

关键词: 非正侧视阵列, 机载雷达, 多普勒频移, 杂波抑制, 空时自适应处理