•Seasonal trajectories of nine bands and six indices from Sentinel-2 were analysed.•Seasonal change values were better for early detection than absolute reflectance.•Tasselled Cap Wetness and ...SWIR-based NDVI were most successful.•Separation of green-attack trees was best in autumn before next beetle generation.
In the past decade, massive outbreaks of bark beetles (Ips spp.) have caused large-scale decline of coniferous-dominated, prevailingly managed forests of Central Europe. Timely detection of newly infested trees is important for minimizing economic losses and effectively planning forest management activities to stop or at least slow outbreaks. With the advancement of Copernicus services, a pair of Sentinel-2 satellites provides a unique remote sensing data source of multi-temporal observations in high spatial resolution on the scale of individual forest stands (although not allowing for individual tree detection). This study investigates the potential for using seasonal trajectories of Sentinel-2 bands and selected vegetation indices in early detection of bark beetle infestation (so–called green-attack stage detection) in Norway spruce monoculture forests in the Czech Republic. Spectral trajectories of nine bands and six vegetation indices were constructed for the 2018 vegetation season using 14 satellite observations from April to November to distinguish four infestation classes. We used a random forest algorithm to classify healthy (i.e., stands not infested) and infested trees with various trajectories of decay. The seasonal trajectories of vegetation indices separated the infestation classes better than did the individual bands. Among the most promising vegetation indices we identified the tasselled cap wetness (TCW) component and normalized difference index constructed from near and shortwave infrared bands. Analysing the inter-annual change of the indices was more promising for early detection than is single-date classification. It achieved 96% classification accuracy on day of year 291 for the tested data set.The algorithm for early detection of tree infestation based on the assessment of seasonal changes in TCW was applied on the time series of Sentinel-2 observations from 2019 and its outputs were verified using field observations of forest conditions conducted on 80 spruce forest plots (located in spruce monoculture stands). The overall accuracy of 78% was achieved for the separation of healthy and green-attack classes. Our study highlights the great potential of multi-temporal remote sensing and the use of shortwave infrared wavelengths for early detection of spruce forest decline caused by bark beetle infestation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Field survey, phenology model, airborne hyperspectral remote sensing were combined.•Remote sensing method using VNIR identified infested trees later than field survey.•Red-edge based indices (REIP, ...ANCB) were more sensitive during early infestation.
Detection in the early phase of bark beetle infestation is a vital task for proactive management strategies, as practiced in most Central European forests, to minimize economic losses due to bark beetle infestation and to mitigate their further spreading. For this work, remote sensing methods are coming to be in great demand as an objective approach to enable monitoring bark beetle infestation even at individual tree level.
This case study monitored bark beetle (Ips typographus) activity at local level in Norway spruce forest in the Czech Republic. The main aim of this study was to compare the remote sensing methods against classical field survey conducted by forest workers in detecting newly infested trees.
To compare these two methods, an extensive field and aerial campaign was conducted in the southern part of the Czech Republic during 2020. Bark beetle infestation was monitored by traditional methods (i.e. field survey) on a weekly basis from mid-March to mid-September. During the same period, aerial scans were performed once per month (seven in total) using a CASI-1500 hyperspectral sensor (visible and near-infrared, 400–1000 nm) with spatial resolution of 0.5 m. This work mapped transition from healthy up to red attack of 75 Norway spruce trees that were infested during the same week. The same number of healthy trees were added to the data set for hyperspectral data analysis. Both groups were analysed by vegetation indices, with emphasis on effect caused in the canopy by bark beetles.
The success rate for bark beetle detection is always associated with acquisition time. In order to define the optimal time for data acquisition, we employed a phenology model for I. typographus (RITY 2.0) to take into consideration bark beetle development.
The results of the experiment showed that classic field survey detected infested trees earlier than did analysis using remote sensing data from the visible and near-infrared region. The difference was 23 days for the most successful indices (i.e. REIP, PRI, and ANCB650–720) in our test. Nevertheless, both methods detected the infested trees within 6 weeks after infestation, which is the recommended period for taking measures to prevent bark beetles from spreading further, and thus hyperspectral imagery can be used as a valid information source for bark beetle detection.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The aim of this thesis is to evaluate the building technical and structural condition of the family house in Brno Lisen. The part of the thesis are the plan of methodology, implementation and ...evaluation of the diagnostic work. Selected components were statically evaluated and the possibly variant of the static ensure of building reconstruciton was designed.
A master thesis Theatre and Madness ? Madman as a Dramatic Image and as a Social Role is exploring changing images of Madman´s image in theatre and drama of western culture, from antic to the modern ...ages and in relationship to historical, social and cultural contexts. The goal of the thesis is not the complexity of the research. The thesis is merely interested in selected chapters of theatre tradition, that are partially corresponding with personal creative background, particularly with dramaturgy of a John Webster´s play ?The Duchess of Malfi? in Theatre Disk. The work is aspiring for searching and gaining consciousness of roots of this archetypal image, which is standing at a beginning of theatre creation and represents its deep source and possible danger. This image is intended to be magically fulfilled and overreached by its description.
The Fire Control Systems fulfil the main role in the development of modern weapon systems. Nowadays it can be seen the intensive progress of exclusive parts, altered features and operating principles ...connecting with modern FCS. The paper deals with the marginal problem associated with the unique method of target acquisition system. Moreover, the characterization of the FCS from the perspective of its complexity is also presented in the paper.
In the scheme of Single Frequency Networks (SFNs), all transmitters (TXs) radiate the same signal on the same frequency. The SFN represents an ideal solution for the network planning of 2 nd ...generation Digital Video Broadcasting - Terrestrial (DVB-T2). However, inappropriate steps at the planning of SFNs and DVB-T2 signal configuration can lead to significant decrease in the quality of the received TV signal. This paper deals with the simulation and measurement-based performance study of SFNs used to provide DVB-T2 services in Czech Republic. Professional software (SW) tools are employed to planning and analysis SFNs while measurements in the field are conducted with collaboration of Czech Telecommunication Office (CTÚ). Among others, the obtained results show that the SW tools, in some cases, work with such theoretical assumptions that are not in full accordance with real transmission and reception scenarios. In the future, the outputs of this paper can help in the improvement of SW tools used for planning and analyzing of SFNs.
For the first time, Lu2S3 (undoped and Pr-doped) single crystals were successfully grown from a melt using a micropulling-down (mPD) technique. Customization of the halide mPD apparatus allowed us to ...grow rod-shaped (Ø 2 mm and a length of around 20 mm) crystals of Lu2S3 with a high melting temperature (∼1750 °C). X-ray powder diffraction revealed that the grown crystals exhibit an ε-Lu2S3 crystal structure (α-Al2O3 type, space group R3̅c). Optical and scintillation properties of both undoped and Pr3+-doped Lu2S3 were investigated. Fast 5d→4f Pr3+ luminescence was observed in both photoluminescence and radioluminescence spectra. The presented technology is an effective tool for the exploration of a large family of high melting sulfides. Such materials show promise for applications as scintillators, active laser media, and optoelectronic components.
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IJS, KILJ, NUK, PNG, UL, UM
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