REMOTE SENSING OF ORCHARDS: INFLUENCE OF CANOPY ARCHITECTURE AND OBSERVATIONAL CONDITIONS ON UNCERTAINTIES ASSOCIATED TO KEY CANOPY CHARACTERISTICS ESTIMATES BASED ON 3D MODELS
The effect of canopy architecture in the estimation of biophysical parameters from remote sensing data in orchards is studied through the particular case of vine-yard canopies. Two different approximations (1D and 3D models) are tested to estimate Leaf Area Index (LAI) from canopy reflectance in a total of 31 points within commercial field plots. The results shows that 1D models are not pertinent to describe canopy reflectance in row structured canopies, while including a 3D description of canopy architecture provided satisfactory results (RMSE=0.19). A simulation study was also carried out to evaluate the contribution of observational parameters in the accuracy of LAI and the fraction of absorbed photosynthetically active radiation (fIPAR) estimations from canopy reflectance. The results highlight the effect of rows orientation in the uncertainties in the estimation of both parameters. When sun illuminates perpendicular to rows, the sensitivity of canopy reflectance to fIPAR and LAI is higher, thus providing more accurate estimations than in the case of parallel illumination.
López-Lozano , R., Baret, F., Poilvé, H., Tisseyre, B., Rousseau, J. and Lebon, E. (2011). REMOTE SENSING OF ORCHARDS: INFLUENCE OF CANOPY ARCHITECTURE AND OBSERVATIONAL CONDITIONS ON UNCERTAINTIES ASSOCIATED TO KEY CANOPY CHARACTERISTICS ESTIMATES BASED ON 3D MODELS. Acta Hortic. 919, 19-26
vineyard, LAI, fIPAR, architecture models