A New Algorithm about Transforming from Near-field to Far-field of Radar Target Scattering
In order to meet the approximate plane-wave irradiating condition,adequate large field or compact range system is needed for RCS measurement of large aircraft targets.However,an outside testing field site or a compact range system is very expensive,so a new RCS extrapolation method named Hankel algorithm based on near-distance testing has been presented.According to the fact that objective reflectivity spatial distribution is unchanged with measurement state in ISAR imaging,here the multi-scattering center model is built.Then,the height of stealth target is always short,and the far-field condition can easily be satisfied on vertical plane,so the incident spherical wave is equivalent to cylindrical wave.Once more,the relationship between far-field and near-field is deduced by regarding image of the target as secondary radiating source.Finally,the RCS of target can be obtained with the scattering information of near-field extrapolated at full angular aspect.Taking derivative of the near-field data with respect to frequency in algorithm,the error can be reduced in simplifying formula,and just meet the requirement of stepped-frequency system.The results of simulation and experiments show that the algorithm is precise as well as effective.
Li Nanjing Hu Chufeng Li Ying Zhang Linxi
UAV Specialty Technique Key National Laboratory of Northwestern Polytechnic University Xian 710072,Shaanxi China
国际会议
昆明
英文
2008-11-01（万方平台首次上网日期，不代表论文的发表时间）