Use of COSMO-SkyMed imagery for recognition of geomorphological features in the Martel Inlet ice-free areas, King George Island, Antarctica

Abstract

COSMO-SkyMed (Constellation of Small Satellites for Mediterranean Basin Observation) images in spotlight mode (1 m spatial resolution) were used for recognition of geomorphological features in Martel Inlet ice-free areas, King George Island, South Shetland Islands, Antarctica. This article shows the results from texture analysis and filtering of four X-band images with HH and VV polarization, acquired during fieldworks carried out in January and February 2011. Based on field checking and visual interpretation techniques, we identified several glacial landforms such as moraines, flutes, outwash, arêtes, glacial lineations, meltwater channels, lakes, lagoons, and shorelines. Some glacial linear features, such as lateral moraines, flutings, and arêtes are better identified with VV polarization, while supraglacial debris, debris flow, and shorelines are better discriminated with HH polarization. Meltwater channels, lakes, and lagoons were easily distinguished under both co-polarizations. Focal variance texture analysis and specific kernel size convolution filters yielded the best enhanced images for landform visual interpretation. For this propose, the Wallis adaptative, morphological Close, Prewitt with northwesterly and southeasterly directions, and some high-pass filters described in this study are the best filters. Images processed with these filters can be used for studies of geomorphic changes in Antarctica.