Fig. 3. Simulated leaf reflectance including the effects of fluorescence using the fluorescence–reflectance–transmittance (FRT) model (top and middle left plots) and compact airborne spectrographic imager (CASI) reflectance in the laboratory (middle right plot) and from an airborne campaign (bottom two plots). Top left plot shows simulated fluorescence emission for different values of (ranging from 0 to 0.2), and superimposed on leaf reflectance (top right plot) with peaks at 695 nm (B_L = 30 nm) and 750 nm (B_H = 40 nm), N = 1.5, and C_a+b = 40 µg/cm². Derivative reflectance (middle left plot) for different fluorescence simulations shows a double peak as function of fluorescence emission. Laboratory CASI reflectance from sugar maple seedlings with and without fluorescence emission shows that such effects are captured on the derivative reflectance (middle right plot). Airborne CASI data collected over 30- x 30-m sugar maple study sites (bottom plots) from the two sites with highest field-measured F_v/F_m and C_a+b (GY41, F_v/F_m = 0.81; C_a+b = 38.8 µg/cm²) and lowest (MD35, F_v/F_m = 0.75; C_a+b = 19.08 µg/cm²) show comparable double peak features.