Simulation Analysis Of Near Field Scattering Characteristics Of Targets Based On Method Of Moments

The scattering characteristics of the target are mainly expressed as the RCS, and the traditional method of measuring the RCS is measured in the far field. Compared to the far field measurement, the near field measurement method has the advantages of convenient operation, large information and high security. In this paper, the RWG moment method is applied to simulate the scattering near field of the target. Then, the algorithm of near-field to far-field transformation is applied to solve the monostatic RCS distribution of the target by a monostatic near field value. The main work of this paper is as follows:Firstly, the near-field to far-field transformation algorithm and the correlation dimension reduction algorithm are derived, which is used to solve the RCS of target. The specific process of the target's scattering near field is calculated by using RWG moment method.Secondly, the monostatic far field RCS of a plate is calculated by the near-field to far-field transformation algorithm. A half wave dipole is used as the transmitting and receiving antenna. The distribution of the scattering near field is calculated by using the RWG moment method. The monostatic RCS is calculated by using the near-field to far-field transformation algorithm and compared with the far field monostatic RCS. The RCS of the near-field to far-field transformation of the plate is studied at the VV polarization and the HH polarization. The error between the separately modeling and unified modeling are studied by using the RWG moment method to calculate the scattering near field of the target. It is found that the error decreases with the increase of the distance of the near field testing, and it can reduce the computation time, so the method of separately modeling is used to calculate the scattering near field.At last, the error of the near-field to far-field transformation is analyzed. The influence of the near field test range, the sampling points spacing and the frequency interval on the results of the near-field to far-field transformation is studied. Then the near-field to far-field transformation RCS of a polyhedral object is determined by using the plate as the standard body. Compared the results with the far field monostatic RCS, the accuracy of the calibration method is verified.