## 3 Results  
### Comparison between Airborne and DART-Simulated Reflectances  
The assessment of LUT reflectances acceptability with regard to those measured by AVIRIS-C was done in two steps. First, DART-simulated reflectances of each LUT were plotted and compared to the reflectances measured by AVIRIS-C at the associated date (see, for example, Figure 5). All LUTs consistently overestimated canopy reflectances between 0.75 and 1.1 \(\upmu\)m, with the mean image reflectance being either barely within or below LUT reflectances near the red-edge. Image reflectances in the visible and SWIR regions were, however, within simulation ranges.  
Figure 4: Diagram showing one LAI validation point (red dot) within its 20 \(\times\) 20 m plot (bold square). The validation point falls within the AVIRIS-C pixel in red. Other pixels are represented by the grey grid. LAI is derived from 3 digital hemispherical photographies (DHP) taken at various locations within the plot, each one covering an area approximated by a dashed circle.  
Secondly, the amount of pixels that could be explained by the LUTs was evaluated. The percentages of pixels explained by the LUTs within each image are given in Table 6. LUT reflectances encompass image reflectances at various degrees depending on the spectral intervals considered (INT LAI, INT CAB, INT CAR). On average, 54% of pixels' reflectances completely fall within the LUT reflectance boundaries for INT LAI. This goes up to 67% and 97% for INT CAB and INT CAR, respectively. When considering the vegetation indices computed from both images and LUT reflectances, pixel-derived vegetation index (VI) are within LUT-derived VI boundaries from 90% to 100% of the time (excepting summer 2017, which has one occurrence at 83%), depending on the VI considered.  
\begin{table}
\begin{tabular}{l c c c c c c c c c c c} \hline \hline  & & & **2013** & & **2014** & & **2015** & & **2016** & **2017** & **2018** \\  & & **Spr.** & **Sum.** & **Fall** & **Sum.** & **Spr.** & **Sum.** & **Fall** & **Sum.** & **Sum.** & **Sum.** \\ \hline \multirow{4}{*}{LAI} & INT LAI & 32 & 58 & 67 & 62 & 67 & 65 & 53 & 25 & 56 & 55 \\  & NDVI & 99 & 99 & 99 & 100 & 99 & 98 & 97 & 99 & 99 & 97 \\  & MSAVI2 & 96 & 98 & 94 & 99 & 93 & 97 & 90 & 97 & 98 & 96 \\ \hline \multirow{4}{*}{C\({}_{ab}\)} & INT CAB & 46 & 71 & 84 & 82 & 84 & 79 & 71 & 33 & 60 & 62 \\  & MCARI2 & 98 & 98 & 91 & 99 & 97 & 98 & 90 & 98 & 98 & 97 \\  & TCARI/OSAVI & 100 & 100 & 97 & 99 & 100 & 98 & 98 & 93 & 98 & 97 \\  & Maccioni & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 \\  & gNDVI & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 \\  & GM\_94b & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 \\ \hline \multirow{4}{*}{Car} & INT CAR & 100 & 100 & 100 & 100 & 100 & 99 & 100 & 100 & 94 & 78 \\  & R515/R570 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 & 100 \\ \cline{1-1}  & CRI & 100 & 99 & 100 & 100 & 100 & 92 & 100 & 93 & 83 & 68 \\ \hline \hline \end{tabular}
\end{table}
Table 6: Percentages of pixels within AVIRIS-C images which reflectance (for INT LAI, INT CAB, and INT CAR rows) or associated vegetation indices (other rows) are within those derived from the DART LUT.  
Figure 5: Reflectances computed by the DART simulations compared to reflectances of vegetation pixels within the AVIRIS-C image for summer 2014.