Nonlinear Calibration of Polarimetric Radar Cross Section Measurement Systems

Polarimetric radar cross section measurement systems are characterized by polarimetric system parameters ε_h and ε_v. These parameters can be measured by use of rotating dihedrals. The full polarimetric dataset as a function of the angle of rotation can be analyzed with a nonlinear set of calibration equations to yield the system-parameter complex constants and the four polarimetric-calibration amplitudes. These amplitudes appropriately reproduce the system´s drift, and very accurately satisfy a drift-free system-configuration criterion. The results indicate that the nonlinear approach is better than the previously studied linear approach, which yielded system parameters that were seriously distorted by system drift.