indice de végétation par différence normalisée

CONT: Indice de végétation par différence normalisée (IVDN) [ou] NDVI (normalized difference vegetation index]) est un indice de végétation. Le NDVI se calcule à partir des réflectances mesurées dans les bandes visible rouge et le proche infrarouge, [...] où NIR est la réflexion dans la bande proche infra-rouge, et R est la réflexion dans la bande rouge visible.
OBS: indice de végétation par différence normalisée; indice de Tucker; indice d'activité végétale; NDVI : termes et abréviation uniformisés par le Groupe de travail de la terminologie de RADARSAT-2 (GTTR).

CONT: The NDVI has been correlated with such physical measurements as total standing biomass green leaf-area index (LAI) and per cent vegetation cover but is probably best described as a relative measure of vegetation vigor and photosynthetic activity.
CONT: Normalized difference vegetation index (NDVI) is the ratio between the difference and sum of two spectral bands. One band is in the visible spectrum (e.g. avhrr_ch1) and one band in the near IR [infrared] ... NDVI provides an estimation of the health of vegetation and the means of monitoring changes in vegetation over time. Values close to zero mean little or no vegetation and values close to +1 (0.6-0.9) indicate high density of green leaves.
OBS: normalized difference vegetation index; NDVI: term and abbreviation officially approved by the RADARSAT-2 Terminology Approval Group (RTAG).