7 research outputs found
SIMULATING VARIOUS TERRESTRIAL AND UAV LIDAR SCANNING CONFIGURATIONS FOR UNDERSTORY FOREST STRUCTURE MODELLING
Automated Segmentation of Leaves From Deciduous Trees in Terrestrial Laser Scanning Point Clouds
Simulating various terrestrial and UAV LiDAR scanning configurations for understory forest structure modelling
Information about the 3D structure of understory vegetation is of high relevance in forestry research and management (e.g., for complete biomass estimations). However, it has been hardly investigated systematically with state-of-the-art methods such as static terrestrial laser scanning (TLS) or laser scanning from unmanned aerial vehicle platforms (ULS). A prominent challenge for scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on (1) the height of individual understory trees and (2) understory canopy height raster models. We simulate full-waveform TLS and ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines. The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree models. TLS tree height underestimations range up to 1.84âm (15.30â% of tree height) for single TLS scan positions, but combining three scan positions reduces the underestimation to maximum 0.31âm (2.41â%). Combining ULS flight lines also results in improved tree height representation, with a maximum underestimation of 0.24âm (2.15â%). The presented simulation approach offers a complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling
SIMULATING VARIOUS TERRESTRIAL AND UAV LIDAR SCANNING CONFIGURATIONS FOR UNDERSTORY FOREST STRUCTURE MODELLING
Information about the 3D structure of understory vegetation is of high relevance in forestry research and management
(e.g., for complete biomass estimations). However, it has been hardly investigated systematically with state-of-the-art methods such
as static terrestrial laser scanning (TLS) or laser scanning from unmanned aerial vehicle platforms (ULS). A prominent challenge for
scanning forests is posed by occlusion, calling for proper TLS scan position or ULS flight line configurations in order to achieve an
accurate representation of understory vegetation. The aim of our study is to examine the effect of TLS or ULS scanning strategies on
(1) the height of individual understory trees and (2) understory canopy height raster models. We simulate full-waveform TLS and
ULS point clouds of a virtual forest plot captured from various combinations of max. 12 TLS scan positions or 3 ULS flight lines.
The accuracy of the respective datasets is evaluated with reference values given by the virtually scanned 3D triangle mesh tree
models. TLS tree height underestimations range up to 1.84 m (15.30 % of tree height) for single TLS scan positions, but combining
three scan positions reduces the underestimation to maximum 0.31 m (2.41 %). Combining ULS flight lines also results in improved
tree height representation, with a maximum underestimation of 0.24 m (2.15 %). The presented simulation approach offers a
complementary source of information for efficient planning of field campaigns aiming at understory vegetation modelling
Excited state mass spectra of doubly heavy Î baryons
In this paper, the mass spectra are obtained for doubly heavy baryons,
namely, , , , ,
and . These baryons are consist of two heavy
quarks(, and ) with a light( or ) quark. The ground, radial
and orbital states are calculated in framework of Hypercentral constituent
quark model with coul- omb plus linear potential. Our outcomes are also
compared with other predictions, thus, the average possible range of excited
states masses of these baryons can be determined. The study of the Regge
trajectories are performed in (n, ) and (J, ) planes and their
slopes and intercepts are also determined. Lastly, the ground state magnetic
moments of these doubly heavy baryons are also calculated.Comment: 10 pages, 5 figure