Stem branch angle TreeQSM — stem_branch_angle

Calculates the stem branch angle from a TreeQSM.

Usage

stem_branch_angle_qsm(branch)

Arguments

branch: Branch field of a TreeQSM that is returned by read_tree_qsm.

Value

The stem branch angle in degrees. NaN when there are no stem branches.

Details

The stem branch angle is defined as "the median of the branching angles of the 1st order branches in degrees. 0 is upwards and 180 downwards (parallel with the trunk)" (Akerblom et al., 2017 & Terryn et al., 2020).

References

Akerblom, M., Raumonen, P., Makipaa, R., & Kaasalainen, M. (2017). Automatic tree species recognition with quantitative structure models. Remote Sensing of Environment, 191, 1-12.

Terryn, L., Calders, K., Disney, M., Origo, N., Malhi, Y., Newnham, G., ... & Verbeeck, H. (2020). Tree species classification using structural features derived from terrestrial laser scanning. ISPRS Journal of Photogrammetry and Remote Sensing, 168, 170-181.

Examples

if (FALSE) {
# Read tree qsm and calculate the stem branch angle
qsm <- read_tree_qsm(QSM_path = "path/to/qsm.mat")
sba <- stem_branch_angle_qsm(branch = qsm$branch)
}