Research On Radar Target Scattering Center Extraction Based On The Spatial Spectral Estimation Algorithm

Research on the electromagnetic scattering properties of radar target is one of the important fields in radar technology. The information of scattering centers is always used for RCS database modeling, data compression, data interpolation and extrapolation, target recognition, etc. Therefore, the scattering center extraction is of great importance in radar target characteristics researching.Estimation of the number of scattering centers is a key problem in scattering center extraction. In order to estimate the number of scattering centers accurately, in this paper two studies are implemented:(1) A new method for source number estimation is put forward based on the multiple signal classification(MUSIC) algorithm;(2) Based on Singular Value Decomposition(SVD) method, a modified function for detecting source number is proposed. Simulation experiments are implemented under the same condition of white noise and color noise situation respectively. Compared with the information theory criterion(AIC) method, the minimum description length(MDL) criterion method and the Gerschgorin disks estimator(GDE), results show that under low SNR(signal to noise ratio), the two methods both improve the estimation accuracy.Secondly, to estimate the scattering location and scattering amplitude, two studies are implemented:(1) A modified propagator method(PM) is proposed to estimate position parameters of scattering center which is based on geometrical theory of diffraction(GTD). To improve estimation precision under low SNR, the covariance matrix is processed for noise elimination.(2) The process of estimating scatter amplitude by utilizing the method of least squares is modified. Simulation results show that the improved PM algorithm costs a smaller amount of calculation and under high SNR, its estimation precision is higher than the ESPRIT algorithm. Moreover the error of scattering amplitude estimation is reduced by the modified method.Finally, in this paper, the application of scattering center extraction technology in RCS data fitting and extrapolation is analyzed. Consider a one-dimensional target, its backscattering field data and RCS data are obtained by simulation over a certain frequency band. Thus the scattering field of interest frequency band can be calculated based on the parameters. Therefore,the RCS data can be fitted. Simulation results indicate that based on the parameters of scattering center, RCS data fitting and extrapolation are valid.