๐”– Bobbio Scriptorium
โœฆ   LIBER   โœฆ

Global mapping of foliage clumping index using multi-angular satellite data

โœ Scribed by J.M. Chen; C.H. Menges; S.G. Leblanc


Publisher
Elsevier Science
Year
2005
Tongue
English
Weight
736 KB
Volume
97
Category
Article
ISSN
0034-4257

No coin nor oath required. For personal study only.

โœฆ Synopsis


Global mapping of the vegetation clumping index is attempted for the first time using multi-angular POLDER 1 data based on a methodology that has been demonstrated to be applicable to Canada's landmass. The clumping index quantified the level of foliage grouping within distinct canopy structures, such as tree crowns, shrubs, and row crops, relative to a random distribution. Vegetation foliage clumping significantly alters its radiation environment and therefore affects vegetation growth as well as water and carbon cycles. The clumping index is useful in ecological and meteorological models because it provides new structural information in addition to the effective LAI retrieved from mono-angle remote sensing and allows accurate separation of sunlit and shaded leaves in the canopy. The relationship between an angular index (normalized difference between hotspot and darkspot) and the clumping index is explored using a geometrical optical model named ''4-Scale''. A simplified version of the mechanistic hotspot model used in 4-Scale is developed to derive the hotspot reflectance from multi-angle measurements for mapping purposes. An accurate clumping map for areas with significant tree (shrub) covers has been achieved, although further research is required to reduce topographic effects.


๐Ÿ“œ SIMILAR VOLUMES