Orthophoto 2010 Bund — Summer — quasi true — NDVI

The NDVI True Orthophoto is based on ADS80 aerial strips from summer 2010. The NDVI (normalised differentiated vegetation index) is the most commonly applied vegetation index. It is calculated from Near Infrared — Red/Nahem Infrared + Red. **Purpose**: The data were obtained by Grün Stadt Zürich for the further survey of greened flat roofs and roof greening potential in Zurich. The index is based on the fact that healthy vegetation in the visible spectral range (wavelength of about 400 to 700 nm) reflects relatively little and relatively much radiation in the subsequent near infrared range (wavelength of about 700 to 1300 nm). The reflection in the near infrared is strongly correlated with the vitality of a plant the more vital the plant, the greater the increase in the degree of reflection in this spectral range. Other surface materials, such as soil, rock or dead vegetation, do not show such a distinctive difference in the degree of reflection of both areas. This circumstance can therefore serve to distinguish, on the one hand, vegetation covered areas of uncovered areas and also to conclude on photosynthetic activity, vitality and density of the vegetation cover.