1. Using UAV-Based Photogrammetry and Hyperspectral Imaging for Mapping Bark Beetle Damage at Tree-Level
- Author
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Päivi Lyytikäinen-Saarenmaa, Topi-Mikko Tapio Tanhuanpää, Markus Holopainen, Minna Blomqvist, Niko Viljanen, Tuula Kantola, Teemu Hakala, Eija Honkavaara, Roope Näsi, Paula Litkey, Department of Forest Sciences, Laboratory of Forest Resources Management and Geo-information Science, Forest Health Group, Forest Ecology and Management, National Land Survey of Finland, and Maanmittauslaitos
- Subjects
Bark beetle ,bark beetle ,UAV ,Point cloud ,radiometry ,photogrammetry ,dense matching ,Image sensor ,insect outbreak ,lcsh:Science ,Remote sensing ,4112 Forestry ,biology ,Hyperspectral imaging ,Picea abies ,15. Life on land ,biology.organism_classification ,Tree (graph theory) ,classification ,digital surface model ,hyperspectral ,Photogrammetry ,classificaiton ,General Earth and Planetary Sciences ,Radiometry ,Environmental science ,lcsh:Q - Abstract
Low-cost, miniaturized hyperspectral imaging technology is becoming available for small unmanned aerial vehicle (UAV) platforms. This technology can be efficient in carrying out small-area inspections of anomalous reflectance characteristics of trees at a very high level of detail. Increased frequency and intensity of insect induced forest disturbance has established a new demand for effective methods suitable in mapping and monitoring tasks. In this investigation, a novel miniaturized hyperspectral frame imaging sensor operating in the wavelength range of 500–900 nm was used to identify mature Norway spruce (Picea abies L. Karst.) trees suffering from infestation, representing a different outbreak phase, by the European spruce bark beetle (Ips typographus L.). We developed a new processing method for analyzing spectral characteristic for high spatial resolution photogrammetric and hyperspectral images in forested environments, as well as for identifying individual anomalous trees. The dense point clouds, measured using image matching, enabled detection of single trees with an accuracy of 74.7%. We classified the trees into classes of healthy, infested and dead, and the results were promising. The best results for the overall accuracy were 76% (Cohen’s kappa 0.60), when using three color classes (healthy, infested, dead). For two color classes (healthy, dead), the best overall accuracy was 90% (kappa 0.80). The survey methodology based on high-resolution hyperspectral imaging will be of a high practical value for forest health management, indicating a status of bark beetle outbreak in time.
- Published
- 2015