Ionosphere Estimation of the Split-Spectrum InSAR based on IRI Model

Abstract

The accuracy of low frequency space-borne Interferometric Synthetic Aperture Radar (InSAR) is seriously affected by ionospheric path delay. Range Split-Spectrum (RSS) method is a widely-used method to remove ionospheric delay phase from interferogram. This method distinguishes ionospheric component from other non-dispersive components for its dispersive character. However, the estimated ionospheric delays differ a lot with different parameters (including multilook number and filter window). For general remote sensing users, setting above parameters is more subjective and arbitrary, which will finally affect the ionospheric delay correction effect. Based on International Reference Ionosphere (IRI) model, we present a method to determine RSS parameters. Different ionospheric delays estimated by RRS method with different parameters are compared and evaluated referring to IRI. Meanwhile, we find that there is a bias between the ionospheric delays estimated by RSS and IRI. Removing this bias may further improve the effect of ionospheric delay correction.