| With the development of radar technology and electromagnetic scattering theory,many radar target scattering characteristics that can be used for detection and recognition have been found.As one of the electromagnetic scattering characteristics of radar targets,the scattering center can describe the electromagnetic scattering characteristics of the target only through a simple model and a small number of parameters,and has a good correspondence with the target geometry structure,which is very conducive to radar target detection and recognition.In addition,the scattering center also has a certain degree of scalability and has great advantages in data compression.However,obtaining the scattering center of the target requires a large amount of electromagnetic scattering data in a certain bandwidth and angular domain.With the continuous improvement of radar system resolution,the working frequency of the radar is getting higher,and the electromagnetic calculation cost required to obtain radar scattering data is also getting higher.When the structure of the radar target is relatively complex,the problem of unclear mechanism and long calculation time arises when using traditional methods to extract the scattering center.In order to solve these problems,this article conducts in-depth research on the rapid extraction of scattering centers and the correlation mechanism between scattering centers and geometric structures based on the bouncing ray method.The main research work includes the following aspects:Firstly,the scattering characteristics of high-frequency targets,especially the scattering centers,were studied.The scattering centers of typical targets were extracted using reverse methods,and the extraction results were compared with SAR images.The formation mechanism of the scattering centers of typical targets was analyzed using ray tracing technology.At the same time,the shortcomings of reverse methods in mechanism analysis and data acquisition were pointed out.Secondly,high-frequency electromagnetic calculation methods were studied,and a hybrid interpolation method based on SBR was proposed to accelerate the modeling of the scattering center inverse method.A Chebyshev approximation algorithm based on SBR is proposed to accelerate the acquisition of RCS in the angular domain.In the frequency domain,a fast broadband RCS data acquisition method that only requires one ray tracing is proposed.And a hybrid interpolation method combining the two is used to quickly obtain the two-dimensional data required for the inverse modeling of scattering centers.The calculation results indicate that using this algorithm can achieve rapid modeling of typical target scattering centers in the high-frequency region.Effectively improving modeling efficiency while maintaining good accuracy.Finally,the forward modeling method for scattering centers was studied.Based on the analysis of the formation mechanism of target scattering centers and the corresponding relationship between scattering centers and target geometry,combined with ray tracing technology,forward modeling of scattering centers was achieved.This method provides a more efficient and concise model for radar target recognition.Its effectiveness has also been verified through numerical calculations. |
