SCATTERING PARAMETER-ESTIMATION ACCURACY OF ROOT-MUSIC ALGORITHMS IN ELECTROMAGNETIC-WAVE SCATTERING MEASUREMENTS

An application of the superresolution method for the analysis of the e lectromagnetic scattering data is expected to be effective for experim ental verification of the geometrical optics approximation theory and the analysis of multiple paths. There exist many techniques for the su perresolution method. It is desirable to select an appropriate techniq ue based upon the characteristics of the individual algorithms. Among these techniques, the Root-MUSIC method has been proposed; this method enables treatment of the signal attenuating exponentially with respec t to frequency. In the modified Root-MUSIC method, arbitrary frequency characteristics can be treated. This paper investigates the estimatio n accuracy of the scattering center and the attenuation coefficient wh en the Root-MUSIC method and the modified Root-MUSIC method are applie d to the estimation of scattering. With the backscattering data of a c onducting sphere, the estimation accuracy of the scattering parameters versus the signal-to-noise ratio (SNR) and the number of snapshots is investigated by computer simulation. As a result, it is found that th e estimation accuracy of the modified Root-MUSIC method is much better than that of the conventional Root-MUSIC method in the case of a low SNR and a small number of snapshots. Experimental results are also rep orted.