Comparison of two Satellite Imaging Platforms for Evaluating Sand Dune Migration in the Ubari Sand Sea (Libyan Fazzan)
Els, A.;Merlo, S.;Knight, J.;
the international archives of the photogrammetry, remote sensing and spatial information sciences2015Vol. XL-7/W3pp. 1375-1380
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els2015comparisonthe
Abstract
Sand dunes can change location, form or dimensions depending on wind direction and strength. Sand dune movements can be
effectively monitored through the comparison of multi-temporal satellite images. However, not all remote sensing platforms are
suitable to study sand dunes. This study compares coarse (Landsat) and fine (Worldview) resolution platforms, specifically focussing
on sand dunes within the Ubari Sand Sea (Libya). Sand dune features (crest line, dune ridge basal outlines) were extracted from
Landsat and Worldview 2 imagery in order to construct geomorphic maps. These geomorphic maps were then compared using image
overlay and differencing, and the Root Mean Squared Error (RMSE) was used to determine if the mapped dune patterns were
significantly different. It was found that Landsat is a sufficient data source when studying dune patterns within a regional sand sea,
but smaller dunes identified from Worldview data were not capable of being extracted in the data sourced from Landsat. This means
that for studies concerned with the dune patterns and movements within sand seas, Landsat is sufficient. But in studies where the
specific dynamics of specific dunes are required, a finer resolution is required; platforms such as Worldview are needed in order to
gain more detailed insight and to link the past and present day climate and environmental change.