From Glacier Facies to SAR Backscatter Zones via GPR

• Main Authors: Kirsty Langley, Svein-erik Hamran, Kjell Arild Høgda, Rune Storvold, Ola Br, Jack Kohler, Jon Ove Hagen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Kongsvegen; Svalbard; glacier
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.452.4879; http://eo.uit.no/publications/KL-TGRS-08.pdf

Abstract—We present a comparison between data acquired with frequency-modulated ground-penetrating radar (GPR) and satel-lite synthetic aperture radar (SAR). Both radars are polarimetric and operate at a center frequency of 5.3 GHz. The field site is the polythermal glacier Kongsvegen, Svalbard. Along glacier GPR profiles cover the ablation area and the accumulation area, where the latter consists of superimposed ice (SI) and firn. The glacier facies are clearly identifiable on the GPR profiles, although we show that the copolarized response is better for distinguishing different ice zones, whereas the SI–firn boundary is most obvious in the cross-polarized response. A calibrated backscatter coeffi-cient is calculated for the GPR data and compared with the SAR backscatter coefficient. The SAR zones are in very good agreement with the GPR-derived glacier facies. We show that, in the ablation area, the SAR response is dominated by backscatter from the previous summer surface. In the SI and firn areas, it is dominated by sources below the previous summer surface. Index Terms—Backscatter, glacier facies, ground-penetrating radar (GPR), synthetic aperture radar (SAR). I.