Research on Low RCS Target Measurement Precision by High-Resolution Imaging Method

In actual measurement process, it is not possible to erect metal ball directly on low RCS(Radar Cross Section) pylon, therefore verify measurement precision of low RCS target would be very difficult. In order to solve the problem, we will introduce a new verification method that metal ball is installed horizontally with foam column at the top of low scattering carrier, which is placed on low RCS pylon. However, because low scattering carrier and foam column, foam column and metal ball have a rather strong electromagnetic coupling effect, so the way of verification is hard to gain RCS of metal ball alone. So we can first diagnose position of scattering center of metal ball using high-resolution imaging method. Then, the scattering properties of metal ball would be refactored. Finally, RCS measurement and theoretical values of metal ball had been compared and analyzed. Experiments results show that RCS measurement of metal ball is close to its theoretical value in HH polarization and VV polarization at C frequency. The error is no more than 0.2dB at plus or minus two degrees.