Virginia Tech
An Assessment of the Utility of a Non-Metric Digital Camera for Measuring Standing Trees
Abstract
dc:description.abstractA method is set forth which makes use of a commercially available, non-metric, solid-state matrix camera to capture spatial and spectral data from an individual tree bole that can be used to measure characteristics about the stem. In this study diameters and heights were measured and used to estimate the volume of 20 red oak (Quercus spp.) stems ranging in diameter at breast height from 16 to over 60 cm and height from 12 to 20 meters. Images were taken from four orthogonal directions around the each stem. Diameter estimates from matching camera to stem distances (3 to 15 meters) of opposite sides were arithmetically averaged. Two arithmetic averages from perpendicular directions were then geometrically averaged. It was found that locating the camera farther from the tree led to more consistent results over the entire stem while locating it closer to the tree provided the most precise estimates provided the inclination angle did not exceed 45 degrees. This method resulted in geometric mean diameter estimates within ± 4 cm for all heights combined when obtained at a distance of 12 m or greater using a 95 % chi-square maximum anticipated error statistic. Error increases with increased stem height from ± 3 cm to ± 7 cm for heights from 1 to 20 meters. In general, the error is equivalent to 3 times the instrument precision, which varies with distance. Two-thirds of the time volume estimates were within 8 percent, which is quite an improvement over the 30 percent interval afforded by an appropriate volume equation.
Degree
thesis:*- Name thesis:degree_name
- Master of Science
- Level thesis:degree_level
- masters
- Discipline thesis:degree_discipline
- Forestry
- Department dc:contributor.department
- Forestry
- Grantor dc:publisher
- Virginia Tech
- Year dc:date.issued
- 1998
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Clark, Neil A.
- Chair dc:contributor.committeechair
-
- Wynne, Randolph H.
- Committee members dc:contributor.committeemember
-
- Oderwald, Richard G.
- Schmoldt, Daniel L.
Subjects
dc:subject × 8Rights
dc:rights- Statement dc:rights
-
- In Copyright
- Licence dc:rights.uri
Identifiers
dc:identifier.*- Dc Identifier Other
- etd-110298-111109
- OAI identifier oai:identifier
- oai:vtechworks.lib.vt.edu:10919/35575