Using UAV-Based Photogrammetry and Hyperspectral Imaging for Mapping Bark Beetle Damage at Tree-Level

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 OPEN ACCESSRemote Sens. 2015, 7 15468 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.

Cicada (<i>Magicicada</i>) Tree Damage Detection Based on UAV Spectral and 3D Data

“…The use of UAVs has great potential for analyzing tree branch conditions as an early detection of tree health [35]. Besides this potential, most of the studies applying UAV imagery to forest health are based in multispectral bands, as near infrared and red edge, in addition to the traditional visible light bands [35][36][37] as presented in this paper.…”

“…An example of surface reconstruction has been in forest structure [29]. Studies have shown that UAVs can help with species identification [30,31], tree height [26,32], crown delineation [26,33,34], and forest health [35][36][37]. The use of UAVs has great potential for analyzing tree branch conditions as an early detection of tree health [35].…”

ORIENTATION AND CALIBRATION REQUIREMENTS FOR HYPERPECTRAL IMAGING USING UAVs: A CASE STUDY

“…Higher temporal and spatial resolution can be achieved when using UAVs making feasible several detailed analysis that are more complex to achieve with existing remote sensing sensors. Recently, hyperspectral cameras have been adapted for UAV platforms, which are lightweight and some of them acquiring frame-format images (Saari et al, 2009;Honkavaara et al, 2013;Aasen et al, 2015;Näsi et al, 2015). Existing pushbroom based hyperspectral cameras require high grade Inertial Navigation Systems (INS) to provide instantaneous position and attitude and this type of systems are high cost and sometimes heavy.…”

Uas Based Tree Species Identification Using the Novel Fpi Based Hyperspectral Cameras in Visible, Nir and Swir Spectral Ranges

“…The second one collects data in SWIR (shortwave infrared) areas (1100-1600 nm) and it was developed by VTT. The VNIR (visible and near-infrared) camera is completely new prototype; in contrast to previous versions operating in the wavelength range of 500-900 nm Honkavaara et al, 2013;Näsi et al, 2015;Oliveira et al, 2016;Tommaselli et al, 2016), the new camera covers range of 400-1000 nm. The SWIR camera has been experimented in recent studies by Mannila et al (2014) and Honkavaara et al (2016), but is used for the first time in the forested environment.…”