Geology Reference
In-Depth Information
Figure 10.49. The motion vectors are produced from
two sequential Radarsdat‐2 images in HV polarization
separated by one day. Two rotated floes are marked by
white rectangles in image (c). Although the algorithm
does not have a capability to estimate the deformation
of their contours,
Komarov and Barber
[2013] assessed
it manually using the rotation vectors of a few points at
the contour of the floe.
It is worth concluding this section on the following
note. A prototype system for operational ice motion track-
ing has been developed by the Finnish Meteorological
Institute. The system is described in
Karvonen
[2013].
It uses two surface‐based radars at fixed locations at the
coast of the Baltic Sea. Each radar system captures an
image of 40 × 40 km
2
at a resolution of approximately
33 m while rotating. This produces a series of images at
very short time intervals. Traceable ice objects in sequen-
tial images are located using the phase correlation tech-
nique described by equation (10.112). An advantage of
this system is its ability to track the displacement of an
ice object within a few minutes (as opposed to motion
tracking from SAR, which can only be achieved within
1-3 days). Therefore, the speed of ice floes can be deter-
mined more accurately.
