Impacts of Flowing Ionospheric Irregularities on L-band Geosynchronous SAR Azimuth Imaging

Abstract:
Ionospheric scintillation due to small-scale ionospheric irregularities tends to cause significant azimuth decorrelation for the L-band geosynchronous synthetic aperture radar (GEO SAR) system. Generalized ambiguity function (GAF) is employed to evaluate potential impacts of the ionospheric irregularities on GEO SAR azimuth imaging. For GEO SAR, due to the slow scanning of the ionospheric penetration point (IPP) during the ultra-long integration time, the convection velocity of the flowing ionospheric irregularities cannot be neglected any longer, which is specifically taken into account for a more accurate formulation of GAF. Finally, the theoretical model is validated via numerical calculations and Monte Carlo simulations.