In: Wagner W., Szekely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B 
174 
existing bands that may contain (excessively) high noise levels 
and/or are poorly modelled by PROSAIL. 
5. CONCLUSION& DISCUSSION 
The results of the study demonstrated that inversion of the 
PROSAIL model yield higher accuracies for Canopy 
chlorophyll content, in comparison to Leaf chlorophyll content. 
The inclusion of canopy chlorophyll content allows us to assess 
whether canopy reflectance is a better predictor of leaf or 
canopy chlorophyll content. The relationships between 
measured and estimated leaf chlorophyll content were poor in 
all inversion processes which confirms other studies revealing 
similar difficulties in estimating leaf chlorophyll (Baret and 
Jacquemoud, 1994). This is also in line with previous studies 
that have demonstrated poor signal propagation from leaf to 
canopy scale. A careful selection of spectral subset, which 
comprised the development of a new method to subset the 
spectral data, proved to contain sufficient information for a 
successful model inversion. By eliminating wavelength having a 
high AAE (subset II), we eliminated noisy/badly modelled 
wavelengths. Consequently, it increased the estimation accuracy 
of investigated parameters (R2=0.87, RMSE=0.22). Although 
our results confirm the potential of model inversion for 
estimating vegetation biochemical parameters using 
hyperspectral measurements, its applicability to heterogeneous 
grasslands requires further experiments and validation work 
using different hyperspectral data sets. 
Acknowledgements 
The corresponding Author would like to acknowledge the 
assistance of Shahid Beheshti University (SBU), and in 
particular RS & GIS centre at SBU for their support. 
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