Can spaceborne synthetic aperture radar be useful for the mapping of ionospheric disturbances in the Arctic Region?

Abstract

In this work we study the potential of C-band SAR images to map ionosphere disturbances in the Arctic region. This region is a unique region for ionosphere studies due to the characteristics of the geomagnetic field. In particular, we focus on the SAR interferometry technique as means to measure the temporal variation of propagation delay in correspondence of ionosphere disturbances. This technique provides maps of propagation delay differences between the acquisition dates of the two coherent SAR images needed to estimate the propagation delay over the study area. The high spatial resolution of C-band SAR images, in the order of 25 meters could contribute to the study of spatial distribution of ionosphere disturbances. Digisondes, VLF/ELF receivers and the EISCAT radars in the available in the Arctic region provide the time of ionosphere disturbances due to the solar activity, monitored by the ACE satellite. This allows to select the SAR images to process to map the ionosphere disturbances. The typical spatial coverage and acquisition times of Sentinel-1 images over the Arctic region are reported. A numerical analysis is carried out to estimate the expected ionosphere propagation delay in Sentinel-1 interferograms and so the potential of SAR interferometry to map the effects of ionosphere disturbances.