Distortions Imposed by Ionospheric Faraday Rotation Dispersion in Low-Frequency Full-Polarimetric SAR Images

Spaceborne polarimetric synthetic aperture radar (Pol-SAR) systems operating at low frequencies, such as P-band, are significantly influenced by ionospheric Faraday rotation (FR). A novel theoretical model of the effect of FR dispersion on Pol-SAR images is proposed. Three components of the range compression response are derived with the main function accompanied by two accessories. Simulation results indicate that two accessory functions in existence of FR dispersion can be comparable with the main for P-band ultrawideband systems. It can not only lead to range imaging deteriorations but also bring about extra polarimetric distortions. Finally, an airborne P-band Pol-SAR real scene is used for validation.