Sammanfattning

Individual tree crowns can be delineated from dense airborne laser scanning (ALS) data and their species can be classified from the spatial distribution and other variables derived from the ALS data within each tree crown. This study reports a new clustering approach to delineate tree crowns in three dimensions (3-D) based on ellipsoidal tree crown models (i.e., ellipsoidal clustering). An im-portant feature of this approach is the aim to derive information also about the understory vegeta-tion. The tree crowns are delineated from echoes derived from full-waveform (fwf) ALS data as well as discrete return ALS data with first and last returns. The ellipsoidal clustering led to an im-provement in the identification of tree crowns. Fwf ALS data offer the possibility to derive also the echo width and the amplitude in addition to the 3-D coordinates of each echo. In this study, tree species are classified from variables describing the fwf (i.e., the mean and standard deviation of the echo amplitude, echo width, and total number of echoes per pulse) and the spatial distribution of the clusters for pine, spruce, birch, oak, alder, and other species. Supervised classification is done for 68 field plots with leave-one-out cross-validation for one field plot at a time. The total accuracy was 71% when using both fwf and spatial variables, 60% when using only spatial variables, and 53% when using discrete return data. The improvement was greatest for discriminating pine and spruce as well as pine and birch.

Nyckelord

Canopy layers; individual trees; light detection and ranging (lidar); single tree detection; three-dimensional (3-D) model

Publicerad i

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
2014, Volym: 7, nummer: 7, artikelnummer: 2331276

SLU författare

• Lindberg, Eva

  • Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet
    

• Holmgren, Johan

  • Institutionen för skoglig resurshushållning, Sveriges lantbruksuniversitet
    

Associerade SLU-program

Remningstorp


Globala målen

Skydda, återställa och främja ett hållbart nyttjande av landbaserade ekosystem, hållbart bruka skogar, bekämpa ökenspridning, hejda och vrida tillbaka markförstöringen samt hejda förlusten av biologisk mångfald


UKÄ forskningsämne

Fjärranalysteknik
Skogsvetenskap


Publikationens identifierare

DOI: https://doi.org/10.1109/JSTARS.2014.2331276

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/61286