Imaging the Ionosphere Using Polarimetric SAR and GPS

In this paper, we will present ionospheric electron content measurements derived from polarimetric data collected using the Phased Array type L-band Synthetic Aperture Radar (PALSAR) onboard the Japanese Advanced Land Observing Satellite (ALOS). The radar measurements of latitudinal features in different regions under various conditions are compared with 2D and 3D assimilative ionsopheric models that ingest GPS data. The comparisons show consistent results between the SAR- and GPS-based techniques. This indicates that GPS-based techniques could be applied to corrections of SAR data, at least to the first order approximation, that are subject to the Faraday rotation and other ionospheric effects. In addition, while GPS measurements collected from global and regional GPS networks are useful to provide large-scale snapshots of ionospheric TEC maps and 3D densities, polarimetric SAR could become a powerful tool to image the ionosphere in much higher resolutions. The potential of SAR-based ionospheric imaging will be discussed that can significantly enhance our capability of investigating outstanding ionospheric research topics.