Glacier facies of Vestfonna (Svalbard) based on SAR images and GPR measurements

• Published in: Remote sensing of environment 2019-02, Vol.221, p.373-385
• Main Authors: Barzycka, Barbara, Błaszczyk, Małgorzata, Grabiec, Mariusz, Jania, Jacek
• Format: Article
• Language: English
• Subjects: Arctic ice; Backscatter; Backscattering; Classification; Climate change; Coefficients; Data processing; Decomposition; Detection; ERS-2; Glacier facies; Glacier mapping; Glacier measurements; Glaciers; Global warming; Ground penetrating radar; Ground Penetrating Radar (GPR); Ice; Image analysis; Image classification; Image processing; Image segmentation; Internal Reflection Energy; Land ice; Mapping; Mass budget; Mathematical analysis; Polar environments; Polarimetry; Radar; Radar imaging; Radar polarimetry; Remote sensing; Remote sensing techniques; Sensing techniques; Synthetic aperture radar; Synthetic Aperture Radar (SAR); Terrestrial environments; Vestfonna
• ISSN: 0034-4257; 1879-0704
• DOI: 10.1016/j.rse.2018.11.020

The warming climate of the Arctic affects the mass budget of glaciers, and changes in the distribution of glacier facies are indicative of their response to climate change. The glacial mass budget over large land ice masses can be estimated by remote sensing techniques, but selecting an efficient remote sensing method for recognizing and mapping glacier facies in the Arctic remains a challenge. In this study, we compared several methods of distinguishing the facies of the Vestfonna ice cap, Svalbard, based upon Synthetic Aperture Radar (SAR) images and terrestrial high frequency Ground Penetrating Radar (GPR) measurements. Glacier zones as determined using the backscattering coefficient (sigma0) of SAR images were compared against GPR data, and an alternative application of Internal Reflection Energy (IRE) calculated from terrestrial GPR data was also used for differentiating the extent of glacier facies. The IRE coefficient was found to offer a suitable method for distinguishing glacier zones and for validating SAR analysis. Furthermore, results of analysis of fully polarimetric Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) and European Remote Sensing Synthetic Aperture Radar (ERS-2 SAR) images were compared with the IRE coefficient classification. Especially promising method is H-α segmentation, where the glacier zone boundaries corresponded very well with both GPR visual interpretation and IRE classification results. The IRE coefficient's simplicity of calculation makes it a good alternative to the subjective GPR visual interpretation method, where results strongly depend on the operator's level of experience. We therefore recommend for GPR profiles to be used for additional validation of SAR image analysis in studies of glacier facies on the High Arctic ice masses. •5 methods of distinguishing glacier facies based on SAR and GPR data are tested.•IRE coefficient is a good alternative for a subjective GPR visual classification.•H-α classification yields especially good results of glacier zones discrimination.•Wavelength and polarisation of SAR affect ability of distinguishing glacier facies.