back: Normalized Difference Vegetation Index (NDVI)		Vegetation appears very different at visible and near-infrared wavelengths. In visible light (top), vegetated areas (like the Pacific Northwest) are very dark, almost black, while desert regions are light (the Great Salt Lake desert). At near-infrared wavelengths the vegetation is brighter, and deserts are about the same. By comparing visible and infrared light, scientists measure the relative amount of vegetation.