中文摘要：

该文主要分析远场条件下机载正侧阵雷达任意波束宽度杂波在各种阵元间距情况下的自由度．首先从距离波数域出发分析任意波束宽度的杂波在各种阵元间距情况下的空间自由度，然后通过空时等效原理将二维空时杂波转化为一维空间杂波，得到不同系统参数情况下的空时杂波自由度，给出了适用范围广的杂波自由度确定方法。最后通过仿真实验验证了上述分析的正确性．

英文摘要：

This paper analyzes the rank of clutter with arbitrary beamwidth, observed by a sidelooking radar with arbitrary element spacing under the far field condition. The rank of spatial clutter with arbitrary beamwidth and element spacing is first analyzed in the range-wavenumber domain. Utilizing the space-time equivalence, the space-time clutter observed by an array is equivalent to the spatial clutter observed by another array with larger size. Thus,the rank of space-time clutter with arbitrary beamwidth and element spacing can be derived in a similar way and a formula for computating the space-time clutter rank is given. Simulation results are given to verify the validity of the analysis.