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Terrestrial photogrammetric stem mensuration for street trees.
- Source :
- Urban Forestry & Urban Greening; Oct2018, Vol. 35, p66-71, 6p
- Publication Year :
- 2018
-
Abstract
- Graphical abstract (A) A general representation of the camera positioning – showing image overlap in red; (B) photos were captured in a parallel-manner to the measured trees within the sampled windbreak and right-of-ways – note the control point target within multiple images; (C) processing the photos created a 3D model of each study site; (D) stem diameter was measured from 'sliced' point cloud data by selecting two points from opposite sides of each stem. Highlights • Tree stems were photographed to create 3D structure from motion (SfM) photogrammetric models. • Diameters at breast height measurements from photogrammetric models were highly correlated with physical measurements. • Photogrammetric point clouds can be used to measure stem DBH, and the point clouds can provide a 3D record the modeled stem. Abstract Much of forest science is dependent on accurate stem measurements, and relatively new photogrammetric techniques may be suitable for modeling stems from the terrestrial perspective. From imagery taken along a windbreak and urban roadways we tested the viability of photogrammetric modeling for producing accurate diameter at breast height measurements. Treatments for different point cloud models differed based on intervals between control points (i.e., every 5 m, 10 m, 25 m, and an absence of target control points) and site conditions (i.e., urban mixed species vs. a windbreak of Pinus taeda) over 100 m sections in the Tampa Bay, FL area. Stem diameter measurements from both the windbreak (n = 53) and the urban sites (n = 93) showed high conformity between field-derived and point cloud model measurements (linear regression showed R<superscript>2</superscript> values >0.9 and RMSE values ranging from 7.04 − 12.35%) with the number of control point targets having little influence on modeled DBH accuracy. Modeled stems of larger trees had greater associated error relative to DBH tape measurements, which can be attributed, in part, to problems with estimating diameter from non-circular stems of certain urban species (i.e., Quercus virginiana). Future work will focus on georeferencing these datasets and extracting data on other aspects of stem biometry (e.g., lean angle of stem, stem volume, etc.). [ABSTRACT FROM AUTHOR]
- Subjects :
- URBAN trees
PHYSICAL measurements
PHOTOGRAMMETRY
URBAN forestry
ARBORICULTURE
Subjects
Details
- Language :
- English
- ISSN :
- 16188667
- Volume :
- 35
- Database :
- Supplemental Index
- Journal :
- Urban Forestry & Urban Greening
- Publication Type :
- Academic Journal
- Accession number :
- 132033650
- Full Text :
- https://doi.org/10.1016/j.ufug.2018.07.016