Simulating and mitigating ionospheric effects in synthetic aperture radar

The ionosphere is magnetized plasma that forms above the neutral atmosphere due to solar ionization of upper atmosphere constituents. It presents an obstacle to space based synthetic aperture radar (SAR) systems since it affects the radar signals traveling through it. Its impact can be split into two groups: uniform effects (those caused by a spatially uniform non-turbulent ionosphere) and nonuniform effects (those caused by irregularities in the ionosphere). In this paper, we present a method for simulating the uniform non-turbulent effects such as dispersion, group delay, Faraday rotation, and phase shift. This method is then validated using PALSAR data of Washington, DC. We also show the coherence in this scene after ionospheric effects are added. Finally, the model is used to predict the level of ionospheric effects in future space based SAR systems such as ALOS-2.