282 
Chlorophyll-a (mg/m3) 
Fig. 4. The Chi 
concentration 
versus 
(a) 
the 
ratio 
of 
peak 
magnitude 
(Rmax) 
to the reflectance 
at 
670 
nm ; 
(b) 
the 
reflectance 
line 
height (RLH) 
near 7 00 
nm. 
The 
base 
line 
was 
positioned from 670 throughout 850 nm. 
1993). Therefore, the reflectance line height (RLH) may be used 
as a measure of Chi concentration (Fig. 4b). 
RLH retrieved from reflectance spectra was compared to 
actual Chi concentration from the March data set (r 2 =0.93): 
Chi = 0.35 + (40.37+1.67)*RLH, mg.m -3 (6) 
The validation of Eq. 6 was made using an independent data 
set obtained in April. Calculated using Eq. 6. Chi concentrations 
were compared to the measured in-situ . The r 2 between predicted 
and actual Chi concentration was > 0.97 and an estimation error 
of chlorophyll of less than 6.47 mg.m -3 was obtained (Fig. 5). 
Ki 
ri' 
Chlorophyll-a Measured (mg/m3) 
Fig. 5. Validation of the model presented in eq. 6 by the data 
set acquired in April. 
CONCLUSIONS 
1. The fluorescence line height at 690 nm above the base 
line through 670 and 750 nm, and a sum of reflectance above