Towards an Interferometric Autofocus for the Estimation of Ionospheric Signatures in Biomass

Abstract:
This paper presents the workflow towards an improved estimation and correction of phase errors due to trans-ionospheric propagation in low-frequency Synthetic Aperture Radar (SAR) images when interferometric stacks are available. The method consists of estimating the absolute ionospheric phase delays in each of the images with traditional methods like autofocus. These setimations will later be combined with what is obtained during the correction of the differential ionosphere in interferometric pairs. By running the algorithms on simulated data, it is shown that it is possible to resolve faster changing phase errors than with the autofocus alone for a more accurate correction.