Imaging Ionospheric Perturbations Using L-band Space-Borne Radar

Space-borne synthetic aperture radar (SAR) is a powerful radio technique for imaging Earth topography and surface deformation, terrestrial biomass structure, and ice dynamics. Operating at L-band with full polarimetric or/and split-spectrum capability, such a radar can also provide measurements to image the ionosphere globally. In this paper, we will present 2-dimentional ionospheric images obtained by processing polarimetric SAR data collected using the Phased Array type L-band Synthetic Aperture Radar (PALSAR) on board Japanese Advanced Land Observing Satellite (ALOS). The Faraday rotation features with relatively high resolutions captured in the radar images are compared with ambient ionospheric conditions measured using GPS signals monitored at distributed ground stations of the International GPS Service (IGS). The comparisons are made for polar and low-latitude regions to capture ionospheric fine structures associated with auroral activities under perturbed space weather conditions and with plasma irregularities. With the radar techniques, we anticipate that the planned NASA space-borne radar missions such as DESDynI and SMAP will provide unprecedented opportunities to image the ionospheric fine structures globally in addition to their primary Earth science observations.