Method for Estimating Scatterer Information from the Response Waveform of a Backward Transient Scattered Field When a Line Source and an Observation Point are at Different Positions

This paper proposes a method for estimating scatterer information from the response waveform of a backward transient field for E-polarization scattered by a two-dimensional (2-D) coated cylinder when an electric line source and an observation point are at different positions. The three types of scatterer information treated in this paper are the relative permittivity of a coating medium layer, its thickness, and the outer radius of a coated cylinder. Specifically, the time-domain Fourier transform method (TD-FTM) and the amplitude intensity ratios (AIRs) of adjacent backward transient scattered electric field components are used to derive estimation formulas. The estimates are obtained by substituting the numerical data of the response waveform and the numerical parameters of a pulse source into the estimation formulas and performing iterative calculations. The effectiveness of the estimation method is verified by comparing the estimates with the set values.