Characteristic Polarization States in an Ultrawideband Context Based on the Singularity Expansion Method

The concept of characteristic polarization states (CPSs) is extended to an ultrawideband (UWB) context by a time-domain approach. This is achieved by a sparse representation of the target UWB temporal response by the singularity expansion model. The polarization description uses the complex residues and frequencies associated with each singularity mode to derive both coherent target polarization scattering information and, subsequently (using the Lagrangian optimization procedure), a set of CPSs associated with the singularities of interest.