Geology Reference
In-Depth Information
ALASKA
CANADA
SIBERIA
GREENLAND
SCANDINAVIA
Figure 10.47
Ice displacement field over the entire Arctic from January 9-11, 2003 retrieved from enhanced‐res-
olution QuikSCAT HH and VV polarization composites, superimposed on the HH polarization image. Light gray
area marks domination of MY ice and dark gray is FY ice. Successful node displacement results are shown as
white flags, interpolated displacement nodes in black [
Haarpaintne
, 2006, Figure 1, with permission from IEEE].
images. In addition to the tracking errors there is also the
error caused by the discretization constraints of the pixel
size. For example, if the size of the SAR pixel is 100 m, then
the horizontal and vertical components of the displace-
ments are constrained to multiples of 100 m. This affects
the small motions between points rather than large motion.
upcoming ERS and Radarsat SAR data. The purpose
was to utilize the huge volume of SAR data over the
Arctic to map ice parameters and surface features at a
fine scale (i.e., hundreds of meters). This would allow
for the extraction of ice displacement and motion vec-
tors within small leads provided that they are not
exposed to intensive dynamics. A preliminary system,
called Geophysical Processor System (GPS) was devel-
oped by JPL and installed at the University of Alaska,
Fairbanks, as part of the Alaska SAR Facility (ASF)
[
Kowk et al
., 1990]. This system was dedicated to process
the European ERS SAR data. The ASF facility consists
of three subsystems: a receiving ground station, a high‐
speed SAR processor, and an archive and operations
system that supports the GPS. The GPS produced three
different data products: sea ice motion vector data, sea
10.7.2. Radarsat Geophysical Processor System
It has been recognized that the coarse resolution
of the radiometers and scatterometers is not sufficient
to resolve single lead or coastal polynya openings.
Therefore, with the advent of SAR in the early 1990s
the Jet Propulsion Laboratory (JPL) in Pasadena,
California, embarked on a project to develop a high‐
speed SAR processor to retrieve ice parameters from the
