Target decomposition and polarimetric radar applied to concealed threat detection

Abstract

Target decomposition is of interest to the security and defence community as it enables data sets to be reduced to their principal identifying components as a pre-processor to running pattern recognition algorithms. An investigation into the application of target decomposition theory for concealed threat detection is presented. A validation study has been conducted in which the scattering of an EM wave by a number of primitive radar calibration targets has been simulated using an EM FEA solver. A knife has then been illuminated with quad polar radar again in a simulation conducted using an EM FEA solver. The validation of the target decomposition algorithm is achieved by analysing the calibration targets with well-known scattering mechanisms. The decomposition of more complex targets such as those encountered in Concealed Threat Detection (CTD) scenarios are then analysed. The decomposition is performed as prescribed by Cloude et al and the scattering of the illuminating wave due to the target is mapped onto a 3D space detailing polarimetric entropy (H), anisotropy (A) and alpha-angle (α). The decomposition of these complex scattering mechanisms is then used to classify the data. Both theoretical and simulated data sets are used to validate this technique.