SENSITIVITY OF TEXTURE OF HIGH-RESOLUTION IMAGES OF FOREST TO BIOPHYSICAL AND ACQUISITION PARAMETERS

This article presents a quantitive analysis of the sensitivity of text ural information of high resolution remote sensing images of a forest plantation (Les Landes, France) to a number of biophysical parameters: crown diameter, distance between trees and rows, tree positioning, le af area index (LAI), and tree height. Influence of acquisition paramet ers (spatial resolution, spectral domain and viewing, and illumination configurations) is also investigated. The work is realized with the d iscrete anisotropic radiative transfer model (DART) simulated images w ith which we quantify texture with variograms. Results point out the c omplex dependency of variogram characteristics (range, sill, amplitude of oscillations) on biophysical and acquisition parameters. Neglect o f spatial variations of the reflectance of canopy elements, as in most geometric-optical models, can lead to important errors. This stresses the interest of accurate radiative transfer models, such as DART. Alt hough tree crown diameter is the most influential biophysic parameter, its influence may be totally masked by acquisition parameters. Finall y, theoretical results were tested against high resolution airborne da ta (1.67 m resolution). Although encouraging results were obtained, th is work both confirms the difficulty of extracting reliable texture in formation from real remote sensing data, and stresses the usefulness o f radiative transfer models for studying the texture of high resolutio n satellite images. (C) Elsevier Science Inc., 1998.