High-resolution land cover mapping is needed in the heterogeneous arctic landscapes that change land surface parameters over a range of a few meters. Polygonal tundra on Samoylov Island features a network of dry polygonal rims interspersed with patches of wet tundra and polygon ponds.
In summer 2007, high-resolution aerial images were obtained by mounting a Nikon D200 (visible range) to a helium-filled balloon. Acquisition dates were July 4, 21, 23 and 26, 2007. Flying heights ranged between 620 m and 970 m leading to an average resolution of 0.33 m for the single images. A network of 26 ground control points were set up to calculate image orientation. For more information on the camera system and the local cartesian coordinate system see Scheritz et al. (2008, hdl:10013/epic.30127.d001).
25 images were selected to cover the whole island. Images included both nadir and oblique images that resulted in strong color differences between the images that could not be completely corrected. Images were orthorectified and mosaiked in ERDAS IMAGINE (http://geospatial.intergraph.com) to create an orthophoto with a resolution of 0.7 m. The resulting orthomosaic was transformed from the local coordinate system to UTM (WGS84, 52N).
The total area of Samoylov Island is 4.34 km**2 with the elevated polygonal tundra in the west of the island encompassing 2.85 km**2 and the lowered eastern flood plain having a size of about 1.49 km**2. Although local color differences hinder pixel-based classification, geomorphological units, i.e. polygon centers, polygon rims and polygon ponds are clearly detectable.
"Other version" links to an overview image in jpg-format.