Recent Advancements in Optical Field Leaf Area Index, Foliage Heterogeneity, and Foliage Angular Distribution Measurements

In-situ estimations of leaf area index (LAI), leaf clumping, and leaf angular distribution are often performed from canopy gap fraction measurements with optical sensors. Two new procedures are used in this study to improve the estimation of gap fraction from digital camera photographs,: 1) the Digital Number (DN) of mixed sky-canopy pixels is use to estimate the within pixel gap fraction instead of the usual threshold used to separate a pixel …