New UWB free-space method for the classification and characterization of dielectric objects

This paper presents a new approach for the accurate free-space characterization of irregularly shaped and arbitrarily oriented dielectric objects. The objects under test are illuminated by UWB-pulses and the scattered pulses are collected by an array of receiving antennas. The scattered pulses contain information about the geometrical properties as well as the dielectric properties; a multivariate calibration method is supposed to be able to separate these properties. A classification algorithm is applied prior to the multivariate calibration. It provides a classification into two classes, low or high permittivity. The statistical calibration method is then applied separately in each class. This leads to a significant improvement of the accuracy of the determination of the dielectric properties compared to processing without classification.