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Updated:
14 February 2003
Disclaimer:With all these enhancements and algorithms, it must be noted that the satellite sensor is broad band and the unique discrimination of surface materials is often limited. At best the presented algorithms are an indication of occurrence of the labelled features and some will be more definitive than others. While we have presented a powerful on-line remote sensing analysis tool, there are limitations of algorithms in terms of accuracy. An understanding of the properties of marine and coastal materials and their interaction to produce a complex signal at the satellite sensor is required to properly analyse the processed imagery. Variability in scene contents will always result in subjective and relative accuracies of imagery.
NDVI AlgorithmThis algorithm is the standard Normalised Difference Vegetation Index (NDVI = (b4 - b3)/(b4 + b3)) for Landsat TM. This algorithm enhances the differences between band 3 and 4 due to leaf chlorophyll relative to the combined radiance of those bands. This algorithm may be influenced by surface fe-oxide distribution where the vegetation density is low. |
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