Polarization-Frequency Trajectories of Invariant Characteristics of UWB Remote Sensing Objects

Ultra-wideband remote sensing of Earth's surface allows getting the high-resolution images, and application of multichannel polarimetric radars increases their informativity for solving tasks of detection, classification and recognition of objects. Polarization of signals backscattered from remote sensing objects depends on objects form, their electrophysical properties and sensing frequency, that gives the opportunity of objects classification and recognition. However, the polarization of reflected signals also depends on objects orientation in the plane of the incident electromagnetic wave front that leads to essential fluctuations of reflected signals parameters. The paper proposes for the description of objects polarization characteristics to use the invariant coherent decomposition of polarization scattering matrix based on eigenvalues and eigenvectors of the polarization scattering matrix, which allow determining polarization transfer functions of remote sensing objects, and to present their frequency dependence in the form of polarization-frequency trajectories on a polarimetric diagram. The dependencies of objects eigen polarizations and polarization transfer functions on the frequency of sensing signal are got using a simple mathematical model and presented in form of polarization-frequency trajectories, which can be used as polarization signatures for classification and recognition of remote sensing objects.