Layer-optimized SAR processing with a mobile pRES to illuminate the internal layering of an alpine glacier
- 1University of Tübingen, Department of Geoscience, Tübingen, Germany
- 2British Antarctic Survey, Cambridge, United Kingdom
- 3University College London, Department of Electronic & Electrical Engineering, London, United Kingdom
- 4Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany
- 5University of Bremen, Department of Geosciences, Bremen, Germany
The internal, isochronous layering of glaciers is shaped by accumulation and ice deformation. Information about these processes can be inferred from observing the layers using radar sounding. The reflectivity of the layers depends on density (permittivity) and acidity (conductivity) contrasts which tend to decrease with depth. At places like alpine glaciers where logistic limitations often only allow the deployment of lightweight and power-constrained ground-penetrating radar systems, it can therefore be challenging to illuminate the deeper radio-stratigraphy.
The phase-sensitive Radio Echo Sounder (pRES) is a lightweight frequency modulated continuous wave radar which allows the use of coherent Synthetic Aperture Radar (SAR) processing techniques to improve the signal-to-noise ratio of internal reflection horizons. Using a mobile pRES we collected a radar profile on an alpine glacier (Colle Gnifetti, Italy/Switzerland). Here, we demonstrate how to apply layer-optimized SAR techniques to make deep internal layers visible, which could not be seen by a conventional pulsed radar. We evaluate the requirements on spatial resolution and positioning accuracy during data acquisition, necessary for applying layer-optimized SAR processing, as they constrain the feasibility of the method. We further discuss implications on how density and acidity contribute to decreasing dielectric contrasts.
How to cite: Oraschewski, F. M., Koch, I., Ershadi, M., Hawkins, J., Eisen, O., and Drews, R.: Layer-optimized SAR processing with a mobile pRES to illuminate the internal layering of an alpine glacier, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9273, https://doi.org/10.5194/egusphere-egu23-9273, 2023.