Apogee NDVI Sensors

NDVI (Normalised Difference Vegetation Index) is calculated from measurements of electromagnetic radiation reflected from plant canopy surfaces. NDVI is a standardised index use to measure the state of plant health. Leaf chlorophyll absorbs red light (approximately 680mm), and the cellular structure of the leaves strongly reflect near-infrared light, approximately 730mm. When the plant is water stressed or diseased the spongy layer deteriorates and the plant absorbs more of the near-infrared light (NIR), rather than reflecting it. By observing how NIR changes compared to red light provides an accurate indication of the presence of chlorophyll, which correlates with plant health. Apogee NDVI sensors are designed to measure the reflected Normalised Difference Vegetation Index (NDVI) radiation bands of plant canopies. The spectral ranges cover 650 nm ± 5 nm with 65 full-width half-maximum (Red) and 810 nm ± 5 nm with 65 full-width half-maximum (NIR).