Coral reef habitat maps at various spatial scales and extent are needed for monitoring and management purposes in coral reef environments. This paper will demonstrate objectbasedanalysis for coral reef habitat mappi...
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ISBN:
(纸本)9781424495665
Coral reef habitat maps at various spatial scales and extent are needed for monitoring and management purposes in coral reef environments. This paper will demonstrate objectbasedanalysis for coral reef habitat mapping at reef type, geomorphic zone and benthic community spatial scales, on single reefs or reef systems in Western Pacific. For the study sites, archived high spatial resolution Quickbird and/or Ikonos imagery were acquired and radiometric and atmospheric corrected. Georeferenced benthic photos along transects were acquired for calibration and validation purposes. Hierarchical mapping from reef, to geomorphic zone, then community scales, was completed using objectbased segmentation and semi-automated labeling through membership rules using field data for calibration and validation. The resulting hierarchal maps for reef type, geomorphic zone and benthic community, had varying accuracies 60-80% for each spatial scale.
While analyzing satellite or aerial images different inconveniences can have negative effects on final classification accuracy. The objective of this paper is to expose the problems that were faced while classifying l...
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While analyzing satellite or aerial images different inconveniences can have negative effects on final classification accuracy. The objective of this paper is to expose the problems that were faced while classifying land use and land cover over two study areas in Slovenia. Two differently covered areas were chosen intentionally;the intensive agricultural area of Gornja Radgona in North-Eastern Slovenia and the subalpine area of Kobarid in the Western part of the country. By using object based image analysis we focus on two main problems;reducing negative effects of shadows on the image and misleading delineation of spectrally similar classes. Shadows that are present in the image and inconvenient for the interpretation were divided into two groups;small patches of shadows, which are result of higher objects, and bigger areas of shadows in the mountainous area. Both types of shadows are the consequence of the "inappropriate" position of the Sun at the time of acquisition and significant altitude difference over a relatively short distance. Another issue in the classification process is the delineation of segments that separate classes with similar spectral signature in the segmentation phase. Although segmentation parameters have been optimally set on a value where spectrally similar classes can still be separated, the delineations of classes do not always show the real situation. This paper presents approaches that were used to minimize both aforementioned problems and through which higher final classification accuracy was obtained.
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