LaiPen
measures Leaf Area Index (LAI), defined as one-sided green leaf area per unit ground surface area (m2 per m2) in broadleaf canopies. The LaiPen LP 110 calculates LAI, and other canopy structure attributes, from solar radiation measurements made with a wide-angle optical sensor. Measurements made above and below the canopy are used to determine canopy light interception at five angles, from which LAI is computed using a model of radiative transfer in vegetative canopies.