中文摘要：

针对近场散射测量中由于天线方向图照射的不均匀性,在近场数据外推后难以获得目标准确雷达散射截面（radar cross section, RCS）的问题,提出基于近似函数的天线方向图修正方法,在近场数据外推的过程中对天线方向图进行补偿,从而提高目标RCS测量的准确性。首先推导了近远场变换的计算过程,然后根据收发天线照射目标的角域,分析了与天线方向图吻合的近似函数,通过对近似函数的傅里叶级数展开修正了天线方向图的影响。仿真结果表明,对于不同的天线方向图,该方法在近远场变换过程中具有良好的修正效果。实验分别对点目标和线目标进行了验证,结果表明了方向图修正外推方法的有效性和准确性。

英文摘要：

To solve the problem that it is difficult to obtain the accurate radar cross section （RCS） only by the near-field to far-field transformation due to the inhomogeneity of the antenna pattern, an antenna pattern correction method based on approximate functions is proposed, which compensates the antenna pattern during the process of extrapolating the near-field data, so as to improve the accuracy of obtaining the RCS of the target. Firstly, the process of calculating RCS by using the near-field to far-field transformation is derived. Then the approximate function identical to the antenna pattern is analyzed and the influence of the antenna pattern is corrected by using Fourier expansion in the angular domain the antenna covers. The simulation results show that this method has a good effect on compensating different antenna patterns in the near-field to far-field transformation. The effects on the point target and the line target are verified by experiments. The results show the effectiveness and accuracy of the method.