Simulation Reflectance Models in ecology: potentialities and problems

Abstract

Yebra, M., Chuvieco, E. (2008). Simulation Reflectance Models in ecology: potentialities and problems. Ecosistemas 17(3):23-38.

Simulation  approaches  based  on  Radiative  Transfer  Models  (RTM)  have  been  widely  used  in  the  last  few  years  to  estimate  biophysical parameters from remotely sensed data, thanks to their greater generalization power. However, the operational use of RTM is constrained by the difficulty of providing correct parameterization of the input variables.  This paper reviews the main problems of using RTM to accurately estimate biophysical variables from satellite imagery, highlighting the need for considering ecophysiological relationships between the input variables. A case study, focused on the estimation of shrublands water content from MODIS imagery is presented. The selected RTM were PROSPECT and SAILH. As a result of this exercise, it is shown that the accuracy in the estimations is greatly improved by considering the co-variation between the inputs (average errors about 30% against errors around 50% when using a random variation of input parameters).