https://orcid.org/0000-0002-6259-1841
Figures & data
Figure 1. Study area (Background is hyperspectral imagery collected on 14 June 2016. RGB composition with bands at 800, 650, and 550 nm. Grasslands are surrounded by treelines, as shown in the figure. Yellow dots represent study sites with 2 × 2 m each in size.)
Table 1. Statistics of measured leaf chlorophyll content, decay pigment content, and canopy LAI
Table 2. Leaf properties considered in different versions of the PROSPECT model
Figure 2. Leaf refractive indices for different types of leaves: green (Feret et al. Citation2008), senescent and decayed (Proctor, Lu, and He Citation2017), and an averaged version used in this study
Table 3. Parameters in the PROSPECT and SAIL models. The value ranges for different parameters are selected based on prior knowledge from field measurements or from literature (Verhoef and Bach Citation2007; Feret et al. Citation2008; Jacquemoud et al. Citation2009; Darvishzadeh et al. Citation2011; Mousivand et al. Citation2014; Feret et al. Citation2017; Proctor, Lu, and He Citation2017)
Figure 3. Root Mean Square Error (RMSE) of simulated leaf spectra for photosynthetic (Figure a) and non-photosynthetic leaves (Figure b) with the PROSPECT-5, PROSPECT-D, and PROSPECT-5M
Figure 4. Simulation results of photosynthetic and non-photosynthetic leaves using PROSPECT-5, PROSPECT-D, and PROSPECT-5M (second column) and differences between simulated and measured spectra (third column)
Figure 5. Scatter plots of estimated chlorophyll contents versus measured values using the PROSPECT-5 (a), PROSPECT-D (b), and PROSPECT-5M models (c)
Figure 6. Comparison of original and modified PROSAIL for simulating canopy reflectance with data acquired on (a) 14 June and (b) 26 August 2016
Figure 7. Simulation results of green (Figure A1 and B1) and mixed canopies (Figure C1 and D1) using original and modified PROSAIL (second column) and differences between simulated and measured curves (third column)
Figure 8. Scatter plots of estimated LAI and canopy chlorophyll content versus measured values using the original and modified PROSAIL models for green and mixed canopies (figures a and b correspond to the original model; c and d correspond to the modified model; green color points represent green canopies; brown color points represent mixed canopies)
Figure 9. Comparing PROSAIL estimated canopy-level decay pigment content versus lab measured values
Table 4. Dominant leaf biochemical components of different types of leaves
Figure 10. Absorption coefficients of leaf chemical components that are considered in different PROSPECT models (Feret et al. Citation2008, Citation2017; Proctor, Lu, and He Citation2017). Specific components considered in each model can be found in . Absorption coefficients of brown pigments use arbitrary units (i.e., the secondary y-axis in figure a)
Data availability statement
Parameters in the PROSPECT-5M model, including specific absorption coefficients of initial and advanced decay pigments and decay refractive index, are available from the following repository https://github.com/drproctorWindsor/DecompositionPigments.