National Earth System Science Data Center GLASS Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) Download:
Introduction:
The GLASS FAPAR is approximated by one minus the transmittance of PAR through the entire canopy, which can be calculated from the GLASS LAI product and other information (Xiao et al. 2015a). This algorithm is efficient to estimate the FAPAR values physically consistent with the LAI product. The GLASS FAPAR product from MODIS data is the instantaneous value at 10:30 am local time, close approximation of daily average PAPAR.
The GLASS FAPAR product from AVHRR data is similarly generated. The long-term GLASS FAPAR product was also compared with two similar products and shows high quality and accuracy (Xiao et al. 2018).
References:
[1]Xiao, Z., Liang, S., Sun, R., Wang, J., & Jiang, B. (2015a). Estimating the fraction of absorbed photosynthetically active radiation from the MODIS data based GLASS leaf area index product. Remote Sensing of Environment, 171, 105-117
[2]Xiao, Z., Liang, S., & Sun, R. (2018). Evaluation of Three Long Time Series for Global Fraction of Absorbed Photosynthetically Active Radiation (FAPAR) Products. IEEE Transactions on Geoscience and Remote Sensing, 56, 5509-5524