3-D mapping of a multi-layered Mediterranean forest using ALS data | INSTITUT DE PHYSIQUE DU GLOBE DE PARIS

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  3-D mapping of a multi-layered Mediterranean forest using ALS data

Type de publication:

Journal Article

Source:

Remote Sensing of Environment, Volume 121, p.210-223 (2012)

ISBN:

0034-4257

Numéro d'accès:

WOS:000305051700019

URL:

http://www.sciencedirect.com/science/article/pii/S0034425712000570

Mots-clés:

UMR 7154 ; Géophysique spatiale et planétaire ; Airborne laser scanning; LiDAR; Multi-layered forest; Unsupervised segmentation; Mean shift algorithm; Fuel mapping; Vertical stratification; Tree crown; 3-D mapping; Ground vegetation; Understory; Overstory

Résumé:

This study presents a robust approach for characterization of multi-layered forests using airborne laser scanning (ALS) data. Fuel mapping or biomass estimation requires knowing the diversity and boundaries of the forest patches, as well as their spatial pattern. This includes the thickness of the main vegetation layers, but also the spatial arrangement and size of the individual plants that compose each stratum. In order to decompose the ALS point cloud into genuine 3-D segments corresponding to individual vegetation features, such as shrubs or tree crowns, we apply a statistical approach based on the mean shift algorithm. The segments are progressively assigned to a forest layer: ground vegetation, understory or overstory. Our method relies on a single biophysically meaningful parameter, the kernel bandwidth, which is related to the local forest structure. It is validated on 44 plots of a Portuguese forest, composed mainly of eucalyptus (Eucalyptus globulus Labill.) and maritime pine (Pinus pinaster Ait.) trees. The number of detected trees varies with the dominance position: from 98.6% for the dominant trees to 12.8% for the suppressed trees. Linear regression models explain up to 70% of the variability associated with ground vegetation and understory height.

Notes:

Times Cited: 1