An approach for ionospheric effects reducing on SAR imaging

For low-frequency (UHF/VHF and L band) spaceborne SAR imaging and applications, the ionospheric effects which lead to image defocusing and Faraday rotation can not be ignored. In this paper, a scheme combining Faraday rotation (FR) correction and image defocusing reduction together was presented. This scheme makes use of Faraday rotation estimated from SAR raw data to deduce the total electron content (TEC) disturbance. The soundness of this polarimetric information based technology is analysed and examined by simulations. The result shows that SAR focusing can be improved and the azimuth shift can be calibrated well.