Status and distributions of global mangroves have been mapped using recently available Global Land Survey (GLS) data and the Landsat archive. Approximately 1000 Landsat scenes were interpreted using hybrid supervised and unsupervised digital image classifcation techniques. Each image was normalized for variation in solar angle and earth-sun distance by converting the digital number values to the top-of-the-atmosphere reflectance. Ground truth data and existing maps and databases were used to select training samples and also for iterative labelling. Results were validated using existing GIS data and the published literature to map ‘true mangroves’.
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