A New Faraday Rotation Estimator Based on Polarimetric Coherency Matrix and its Effect on Sea Ice

The influence of the ionosphere on spaceborne SAR signals can be significant, predominantly at the L-band and lower frequencies. In particular, low band polarimetric SAR's applications are mainly limited by Faraday rotation (FR) effects. In this paper a new FR estimator is proposed from linearly polarized coherency matrix data and validated by ALOS PALSAR full-pol data processing. FR angles computed by the new estimator are in good consistent with FR angles computed by physical model. The estimator is also used to assess the impact on sea ice. The results show that a FR value exceeding 2° could reduce the accuracy of geophysical parameter recovery of sea ice in the cross-polarized channels.