Estimation of transition function parameters to evaluate the sensitivity of vegetation indices to leaf area index in a tropical moist forest

Abstract

A non-linear transition function (Lorentzian cumulative function) best represented the relationship between leaf area index (LAI) and spectral vegetation indices (SVI) calculated from a Landsat ETM+ image from a tropical moist forest. The three parameters of the function (transition height, center and half-width) describe the sensitivity of the index to a range of LAI values. From the SVIs tested, the Modified Single Ratio (MSR) had best sensitivity to LAI in this environment being sensitive to changes in LAI from 0.0-4.7.