PERMITTIVITY MEASUREMENTS OF MULTILAYERED MEDIA WITH MONOSTATIC PULSERADAR

Electromagnetic (EM) inversion is a useful tool for quantitative analy sis in short-range applications of pulse radars, To estimate multilaye red media properties using monostatic radar, two inverse scattering ap proaches are discussed: a) layer-stripping algorithm by exploiting amp litude and time delay of radar echoes after their detection, and b) EM inverse problem or parameter optimization by minimizing the mean squa re error between measured and modeled data, Redundancy in the estimati on of media properties is given by spatial continuous measurements of the investigated media, This property is exploited in both the approac hes investigated, In the layer-stripping approach the medium within ea ch layer is homogeneous and the interfaces are assumed laterally conti nuous. In the inverse problem permittivity is assumed to be laterally smooth, implicit smoothing being given in the model parameterization. It is implicit in both methods that the inversion accuracy is strictly related to the amplitude stability of the radar and plane wave approx imation. Therefore, the system calibration and the compensation of som e propagation effects (e.g., near field, losses due to conductivity an d to scattering from particles distributed between layers and on inter faces, pulse distortion) become crucial aspects for each specific appl ication.