Radar Target Poles Extraction And Analysis In Resonance Region

High frequency electromagnetic military target is always in resonance region.Target poles are one of the most important characters of resonance region. To beexactly, extracting poles correctly can take full advantage of high frequency radar,improve its tactic level and lay a solid foundation for radar target identification.First, analyze scattering characters of target in resonance region, based onwhich we come up with a modeling method for complex target. Then two methodsto get transient response in time domain are provided. We decide to use frequencydomain conversion method to get transient response in time domain and this articleprovides the process of conversion in detail. There is a problem that we need toconfirm the starting time of the response in time domain aimed at frequencyconversion method. In this article, this moment can be got based on the direction ofincident wave and the location of target in coordinate system.Simulating and researching beam parameter of Matrix pencil method, we canget the best value. This article proposes a method to confirm poles number whichdoesn’t need any prior estimation of target poles and fits well on any kinds oftargets. It also proposes a method to confirm the starting time of late-time responseadaptively based on relevant standards, because the extracted precision of polesdepends on the starting time of late-time response. To cancel false poles, this articlecomes up with a method to select dominant poles. However, this method mightcancel real poles when deletes false ones. In order to overcome this deficiency, wecan integrate poles that are extracted in many directions. It provides extractingprocess of complex target poles at last, and extracts poles on cuboid and Burkdestroyer target.Directional invariance and the effect which noise has on poles precision arediscussed in this article. Then another representation of poles is given comparedwith resonant circuit. It also researches the physical meanings of quality factor andresonant angle frequency. We analyze the changes of poles when change the featuresize of cuboid and the characters of poles calculating surface current on thefrequencies at poles. Then analyze poles characters of simple assembly and obtainsome useful conclusions.