Measuring Sea Ice Deformation with Imaging RADAR Satellites,
ALASKA UNIV FAIRBANKS GEOPHYSICAL INST
Pagination or Media Count:
Sea ice pack motion can be detected by comparing pairs of geolocated remote sensing images separated in time by a few days. Pattern recognition algorithms have been applied to develop automatic systems for synthetic aperture radar SAR images such as SEASAT and ERS-1. These systems produce a vector field of pack ice displacements. To apply this velocity data to basic problems concerning the distribution of ice types and thicknesses, it is necessary to obtain an accurate measure of the deformation due to opening and closing of leads and to rafting and ridging of floes with each other and with thin new ice. Preliminary studies indicate that the ice motion is piecewise continuous with shear zones separating more rigid continuum elements made up of many floes. We postulate a turbulent regime for the velocity field which leads to the assumption of simple rotational motion for the continuum elements. Applying image analysis techniques to the displacement vectors enables classification and parameterization of the continuum elements and the characteristic discontinuities which border them. Computations based on this analysis can then quantify the deformation internal to the continuum elements and that due to the relative motion between them.
- Snow, Ice and Permafrost
- Cartography and Aerial Photography