Proposal of a Ground Penetrating Radar System Utilizing Polarization Information by Using Phasor-Quaternion Self-Organizing Map

Abstract

Previously we proposed a ground penetrating radar (GPR) system employing complex-valued self-organizing maps (CSOM) to deal with feature vectors based on the frequency and spatial correlation of scattering parameters. It performs unsupervised grouping to achieve visualization. However, this method sometimes shows problems of unclear boundary and shape distortion of a detected object. In this paper, we propose a novel method, phasor quaternion self-organizing map (PQSOM), based on the Poincare vectors combined with phase, which are organized in phasor quaternion (PQ) form. By considering both the polarization state and the phase information as respective counterparts, PQSOM is able to self-organize more effectively, which in turn leads to better grouping performance. Through visualization experiments of landmines, we find that PQSOM has better grouping results compared with CSOM and QSOM.