飞行器RCS近场三维成像的几何设计与性能分析

飞行器隐身设计是先进飞行器总体设计的关键环节，随着更为复杂的结构以及新兴复合材料应用于飞行器制造，基于缩比模型的电磁散射特征分析变得不再精确，在室内或者室外较小区域内开展对全尺寸飞行器电磁散射特征的近场成像与诊断已经成为高效率评估隐身特性的重要方式，受到国内外的广泛关注。本文介绍了两种典型的飞行器近场成像几何，基于球面波分解理论分别建立了信号模型，推导了频域成像处理算法，对比分析了两类不同成像几何对应的成像处理流程，提出子孔径成像处理是分析飞行器电磁散射特征的基本策略；归纳了平面阵列三维成像与柱面阵列三维成像在成像处理复杂度、点散布函数、应用特点等方面的区别与联系。文中通过仿真数据的三维成像验证了所提信号模型与处理算法的正确性。

The Imaging Geometry Design and Performance Analysis of Near-field 3-D Imaging According to Aircraft’s RCS

? ?Aircraft stealth design is a key link in the overall design of advanced aircraft. As more complex structures and emerging composite materials are applied to aircraft manufacturing， the analysis of electromagnetic scattering characteristics based on scaled models becomes no longer accurate. Carrying out near-field imaging and diagnosis of electromagnetic scattering characteristics of full-scale aircraft in indoor or outdoor small areas has become an important way to evaluate stealth characteristics with high efficiency， It has received extensive attention at home and abroad. In this paper， two typical aircraft near-field imaging geometries are introduced. Based on the spherical wave decomposition theory， the signal models are established respectively， and the frequency-domain imaging processing algorithm is derived. The corresponding imaging processing processes of two different imaging geometries are compared and analyzed. It is proposed that sub aperture imaging processing is the basic strategy for analyzing aircraft electromagnetic scattering characteristics； The differences and relations between planar array 3D imaging and cylindrical array 3D imaging in imaging processing complexity， point spread function and application characteristics are summarized. The correctness of the proposed signal model and processing algorithm is verified by three-dimensional imaging of simulation data.