Performance and application of different image matching algorithms for investigating glacier and ice-shelf flow, permafrost creep and landslides

This study focuses on evaluating image correlation methods for deriving surface velocity fields of glaciers, ice shelves, rockglaciers and landslides from both repeat optical and synthetic aperture radar (SAR) images. Firstly we show that low resolution MODIS images (250 m spatial resolution) can in fact be used for determining displacements on Antarctic ice shelves. In this particular case, orientation correlation operated in the frequency domain and using only the phase part of the signal performs better than normalized cross-correlation operated in the spatial domain. Secondly we demonstrate that for determining subpixel displacement when using normalized cross-correlation, image intensity interpolation before the matching process outperforms interpolation of the correlation peak after the matching. We also study methods for adaptively varying the matching template size in order to create the most reliable and accurate matches. The last part of the work shows some application studies of glacier flow from optical and SAR images, rockglacier creep and land sliding.