Sample Products

The actual ice motion data files are just lists of numbers of the form: x1, y1, x2, y2 where (x1,y1) are the initial coordinates of a grid point, at the time of the first image, and (x2,y2) are the final coordinates of the grid point, at the time of the second image. The points (x1,y1) lie on a regular 5-km grid.

One way to display the data is in the form of VECTORS. In this example, the vectors are drawn relative to the motion of the ship, which is at the black dot in the center. The actual ship drift is printed in blue (8.1 km) and its direction is shown by the blue arrow in the upper right corner. The green squares are placed underneath those displacement vectors that differ from the local mean displacement by more than a certain threshold. Thus they highlight the regions along which the ice motion changes abruptly.

Another way to display the same data is via a DEFORMED GRID. This shows how the initially regular grid has changed over the course of one day. The black dot at the center is the ship location. The cells shaded in green are those which have deformed by more than a certain threshold.