高超声速球模型及其尾迹电磁散射试验研究

介绍了利用X、Ka波段雷达系统在中国空气动力研究与发展中心超高速所弹道靶上测量φ10mm的非烧蚀钢球模型和φ10mm烧蚀铝球模型、铜球模型及其尾迹的雷达散射截面(RCS).模型速度大于5km/s,飞行环境压力为3173~11219Pa,雷达测量方式为x波段单站,Ka波段双站.试验时,模型飞过天线波束区时,雷达系统测量模型及尾迹X、Ka波段的近场雷达电磁散射特性.经过近远场变换,利用"距离-多普勒"的ISAR成像原理对模型及其尾迹进行一维距离成像,得出总体RCS和沿模型及尾迹沿飞行轴线的分布RCS和一维距离像.试验结果表明:在本文试验条件下,钢球模型、铝球模型和铜球模型本体RCS均大于尾迹的RCS;在相同飞行速度和环境压力条件下,铝球和铜球的尾迹RCS均远大于钢球的尾迹RCS.

Experimental investigation on electromagnetic scattering of hypersonic spheres and ionization wakes

In this paper,the radar scattering cross section(RCS) of hypersonic sphere models and ionization wakes have been studied.The models were steel sphere models,aluminium sphere models and copper sphere models with 10mm diameter.The models were launched in ballistic range of CARDC.The model velocity was over 5km/s,and environmental pressure ranged from 3173Pa to 11219Pa.The monostatic X band radar and bistatic Ka band radar were used in the tests.The RCS of the models and ionization wakes were measured by the radar when they flew across antenna main beam.After transforming from near field to far field,the overall RCS and RCS distribution and one-dimensional range profile along flight direction of the models were obtained.The technique of one-dimensional range profile was adopted by theory of ISAR imaging.The results presented both RCS of non-ablation sphere models and RCS of ablation sphere models were far larger than RCS of their ionization wakes.The models signals in X band were easily separated from their ionization wakes.The wake RCS of aluminium sphere models and copper sphere models were far larger than that of steel sphere models.