Simulating the impacts of ionospheric scintillation on geosynchronous SAR

Abstract

This paper studies the impacts of ionospheric scintillation on geosynchronous SAR (GEO SAR). A phase screen model is used to simulate the influence of ionospheric scintillation on GEO SAR. In this model, the ionospheric scintillation status (i.e. the thin phase screen) is generated by employing the Rino equation and the climatological paramters (such as C _k L, p and L ₀ ). When wave passes through the phase screen, it will add a phase disturbance and then propagate in the free space, which is the split step solution of the parabolic wave equation. Then the ionospheric transfer function is derived and used to modulate the SAR echo effected in time-domain. Finally simulations are carrired out to analyze effects of ionospheric scintillation quantitatively. In order to better understand the impacts on GEO SAR imaging, we construct a two-dimensional phase screen based on GEO SAR system parameters, and analyse the influence of ionospheric scintillation on GEO SAR when it operates at different positions. The results indicate that there exists inclined streaks in GEO SAR images cauesd by ionospheric scintillation. The inclination of streaks is different and related to the local magnetic heading of radar beam.