Sensitivity of Polarimetric SAR Interferometry Data to Different Vertical Subsurface Structures of the Greenland Ice Sheet

Abstract

The vertical structure of firn below the surface of the Greenland ice sheet is driven by meteorological conditions like the intensity and duration of melting periods. The formation of ice inclusions through melt-refreeze processes leads to strong scatterers whose vertical distribution influences interferometric coherences. Interferometric coherence profiles from quad-pol SAR data show clear sensitivity to the different subsurfaces of two test sites with different melting periods. The differences in coherence are explained in this study through modelling of the different vertical subsurface structures which is supported by ground penetrating radar measurements. The shown sensitivity demonstrates the potential of polarimetric SAR interferometry to retrieve information about melt-refreeze processes and layering below the surface of ice sheets.