LAI 2000 by Li-Cor Biosciences measures LAI as well as leaf angle distribution characteristics with the help of fish-eye lens camera. It is suitable instrument to measure LAI in woody vegetation.
The hemispherical field of view of the camera is divided in five concentric rings, each one of which measures incoming radiation in the complete range of azimuth angles. Measurements by each ring are done by separate photoelectric sensor. Leaf angle distribution and LAI are calculated by the inversion of Poisson model.
The instrument has been found to be underestimating LAI in corn canopies. It has been found to produce results with reasonable accuracy in woodlands, however researchers suggest omitting observations from outer ring for improved accuracy.
More information about LAI 2000
Facchi, A., Baroni, G., Boschetti, M. & Gandolfi, C. Comparing optical and direct methods for leaf area index determination in a maize crop. J. Agric. Eng. 33–40 (2010). doi:10.4081/jae.2010.1.33
Wilhelm, W. W., Ruwe, K. & Schlemmer, M. R. Comparison of three leaf area index meters in a corn canopy. Crop Sci. 40, 1179–1183 (2000).
Cutini, A., Matteucci, G. & Mugnozza, G. S. Estimation of leaf area index with the Li-Cor LAI 2000 in deciduous forests. For. Ecol. Manag. 105, 55–65 (1998).
Rody, Y. P. et al. Estimates of the leaf area index (LAI) using LAI-2000 and hemispherical photos in Eucalyptus plantations. Ciênc. Florest. 24, 925–934 (2014).