The monitoring of ice sheet movement using multiple spaceborne data fusion: A case study of a remote sensing observation over Russell Glacier in Greenland
Abstract:The changes of ice sheet in Greenland have been traced through various remote sensing observations. However, it was realised that the uncertainties in the observed change of ice sheet were not fully addressed. Therefore, we devised and tested a scheme employing multiple sensor satellite data and the data fusion to spatially and temporally monitor the migration of glacier with high accuracy. The test area was established in Russell glacier in western Greenland where the change of glacier has been obvious for the last century.
Firstly, differential interferometric SAR (D-InSAR) campaigns using ALOS PALSAR pairs were applied to monitor the glacial change. In terms of data fusion aspect, we then employed pixel tracing method by co-registration of ALOS PRISM optical images over target area to compensate for any line-of-sight glacial movement resulted by the D-InSAR analysis. To securely trace individual pixel, high accuracy sub-pixel co-registration algorithm was developed. Meanwhile, PALSAR pairs were also applied to test the amplitude tracking method in the same manner. To address the temporal difference between the acquisition of SAR and optical images, the velocity vectors considering seasonal mean migration were interpolated. At last, the outputs from analyses were incorporated to build an effective 3D movement tracing over Russell glacier.
Furthermore, in order to investigate the glacial migration process, the hydrodynamic simulations employing optical stereo pairs and InSAR DTMs over meltwater outflow channels, such as Akuliarusiarsuup Kuua and Qinnguata Kuussua from Russell glacier, were conducted simultaneously with the tracking of the geometric movement of glacier. The overall results were anticipated to be incorporated for the understanding of long term change of Russell glacier. Based on the output of this case study, the proposed method will be extended into a comprehensive scheme to tackle the issues of ice sheet change occurred in the Greenland.