Investigating the Scattering Characteristics of Artificial Field-Aligned Irregularities Based on T-matrix Algorithm

The artificial field-aligned irregularity (AFAI) in ionosphere can be generated by heating the ionosphere with high-power high-frequency radio waves, and the physical structures of AFAIs are modeled as elongated multiple multilayer plasma cylinders. At relatively low frequencies, AFAIs could work as natural reflectors for long-distance communications. In order to evaluate the performance of AFAI-based communications, it is crucial to obtain the objective radar cross section (RCS) of AFAIs quickly and accurately. On account of the large electrical size of AFAIs, it would be time-consuming to calculate the objective RCS by full-wave simulations, meanwhile, the accuracies of the existing approximated methods are limited in many scenarios. In this paper, the T-matrix algorithm is used for analytically calculating the objective RCS of AFAIs after making reasonable approximations. Compared to the results obtained from full-wave simulations, the errors of objective RCS are within an acceptable range while the computation time is largely reduced. Furthermore, the scattering characteristics of AFAIs at different frequencies are investigated. The proposed method could be readily implemented for investigating and predicting the performance of AFAI-based long-wave communications.