Co-Registration Analysis of Coherent Multitemporal Radargrams

Radar Sounder data provide insights into subsurface geology and are typically analyzed using automatic techniques on single-pass acquisitions. A few preliminary studies have explored multitemporal RS data from the cryosphere. However, challenges related to data co-registration exist because of the acquisition geometry and the characteristics of the targets. This paper examines co-registration accuracy in overlapping bi-temporal RS acquisitions co-registered with coherent and non-coherent approaches to evaluate the importance of the phase signal. We project and co-register overlapping radargram pairs to mitigate the horizontal changes related to the ice motion and vertical variations in mass balance. We used the log ratio to compare the co-registered data and highlight backscattering differences in the radargrams due to residual misregistration (and morphological changes). We analyze overlapping radargram pairs acquired in Antarctica in 2014 and 2016.