Geological mapping in Greenland

Radar sensors, which are sensitive to the morphological and electrical characteristics of the Earth's surface, are often applied in geological investigations. In a project carried out in collaboration with the Danish Lithosphere Center, L- and C-band SAR polarimetry data and C-band across-track-interferometry (XTI) data were analyzed. The data were acquired by EMISAR in 1994 and 1995 over a test site on the East coast of Greenland. The objective of the project was to investigate the utilization of SAR in geological mapping of rugged, glacially moulded terrain.
The project included the generation of an elevation map by means of XTI, an assessment of the potential to map individual lava bands and dikes using SAR images, and an analysis focusing on the use of polarimetric SAR in the classification of different rock and surface types. It was found that an elevation map of the test site can be generated with sufficient spatial resolution and height accuracy. The identification of dikes and lava bands depends on their orientation relative to the radar look direction and the incidence angle of the radar beam on the ground. Polarimetric SAR data alone are not well suited for classification of rock and surface types in the test area because of the complex surface characteristics due to weathering and mass transport.
It was also checked whether satellite SAR data (ERS tandem data) can be used to generate an elevation map of the test site, but phase unwrapping proved extremely difficult in this rugged terrain. (Related projects - see: www.dcrs.dtu.dk)