HR: 0800h
AN: C51B-0300    [Abstracts]
TI: Motion Tracking Approaches for Glacial Studies
AU: * Gens, R
EM: rgens@asf.alaska.edu
AF: Alaska Satellite Facility, University of Alaska Fairbanks, P.O. Box 757320, Fairbanks, AK 99775-7320 United States
AB: This paper reviews the common approaches for tracking glacial motion using synthetic aperture radar (SAR) images. Though SAR interferometric (InSAR) techniques have been used successfully for monitoring glacial motion for slow moving glaciers, this technique has its severe limitations when applied to fast moving glaciers with complex flow patterns. An alternate approach to motion tracking for fast moving glaciers is by using speckle tracking techniques. The speckle tracking correlation techniques are often based either on intensity correlation or coherence calculation. In this research we have used a different approach for speckle tracking. This approach is adapted from routine InSAR processing where intensity and phase information of the complex signal is used to achieve a better co-registration. As part of the processing scheme, areas such as the moving glacier and water bodies that negatively affect the correlation are masked out in the intial co-registration phase when the general offset between the two SAR images is determined. After aligning the two SAR images within a one pixel limit the masked out glacial regions are re-included for further processing. The co-registered images are then subsetted to include only the glacial area of interest over which a regular grid is defined. For individual image chips (grid units) an offset is determined. Measurable offsets are attributed to glacial motion. InSAR processing and the adapted speckle tracking approach have been used for studying the Hubbard Glacier, which is the largest tidewater glacier on the North American continent. Processing results are presented along with the discussion on advantages and limitations of the adapted approach.
DE: 0720 Glaciers
DE: 0758 Remote sensing
DE: 0776 Glaciology (1621, 1827, 1863)
SC: Cryosphere [C]
MN: Fall Meeting 2005