Radar target modeling: a geometric theory of diffraction (GTD) -based a

摘要

Abstract: A new approach to scattering center extraction is developed based on a model derived from the geometric theory of diffraction (GTD). For stepped frequency measurements at high frequencies, this model is better matched to the physical scattering process than the Prony or discrete Fourier transform modeling methods. In addition, the GTD-based model extracts more information about the scattering centers, allowing partial identification of scattering center geometry in addition to determining energy and downrange distance. We derive expressions for the Cramer-Rao bound of this model; using these expressions we analyze the behavior of the new model as a function of scatterer separation, bandwidth, number of data points, and noise level. We compare these results with those for the Prony model. Additionally, a maximum likelihood algorithm for the model is developed. Estimation results using data measured on a compact range are presented to validate the proposed modeling procedure. !22