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Classification of Airborne Laser Scanning Data in Sandstone Landscapes
Tomková, Michaela ; Lysák, Jakub (advisor) ; Potůčková, Markéta (referee)
Classification of Airborne Laser Scanning Data in Sandstone Landscapes Abstract This work is concerned with the classification of airborne laser scanning data in sandstone landscapes called "rock cities". Standard filters do not work reliably in such a rugged terrain covered with dense vegetation and in the results the rock formations are smoothed or even removed from the terrain. The method of classification suggested in this work is based on the procedure used in manual filtration. When exploring a sufficiently dense point cloud in 3D, one is able to distinguish rock formations from trees even though their shapes are similar. In contrast to trees, rock pillars are modeled only by points reflected off the surface and therefore they make concave elevations in the ground. Because of penetration of trees, there are points reflected off a treetop, branches, leaves and also ground under the tree. The proposed method segments a point cloud according to local minima in approximated surface and classifies these objects into classes rock, tree, and mix by inner point distribution. Objects in classes tree and mix are then filtered by lasground function from LAStools. The method was tested with merged point cloud consisted of data from the standard airborne laser scanning of the Czech Republic and experimental...
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Utilization of optical and laser data for modeling forest areas
Jebavá, Lucie ; Potůčková, Markéta (advisor) ; Dušánek, Petr (referee)
The thesis deals with the possible use of optical data for modeling forest area compared with utilization of airborne laser scanning data. At first these two datasets are compared and causes of differences are explained. Then canopy height models are made and object-oriented classification is applied for separation of vegetation stands. Methodical procedure is suggested for delineation and detection individual trees in forest. Then their height is detected. There are summarized and other possibilities for improvement in detection and delineation of trees. The results show that optical data with resolution about 25 cm are suitable for dermining the characteristics of the forest stands up to individual tree level. The outputs of this research can be used for forest inventory. Key words: aerial imagery, image matching, laser scanning, point cloud, forest inventory
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Soil moisture estimation using Sentinel-1 radar data
Outrata, David ; Štych, Přemysl (advisor) ; Potůčková, Markéta (referee)
Soil moisture estimation using Sentinel-1 radar data The main aim of this diploma thesis was to find and quantify the relationship between the intensity of backscatter from the Sentinel-1 radar data and the volume soil moisture at the level of agricultural fields. The research was conducted in three areas, in the first part there were two vegetation-free fields near the Thessaloniki (Greece), and information about soil moisture was obtained from own measurements using a thermogravimetric method. The second part drew data from the freely available ISMN database and the research was carried out on agricultural fields during the vegetation season in northwest Germany. The third part used soil moisture data from the Czech Hydrometeorological Institute (ČHMÚ) and the area of interest was two grassed areas of the airport and one agricultural field. Correlation was measured by calculating the determination coefficient and by using the linear regression an equation for calculating the soil moisture from the radar backscatter was compiled. High dependence has been confirmed when VV polarization with constant surface roughness were examined. In the case of surfaces with varying roughness and vegetation cover, only low correlation was found, similarly with using VH polarization. Key words: radar, SAR, Sentinel-1, soil...
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Automatic detection of zebra crossings from aerial images
Tomíček, Jiří ; Potůčková, Markéta (advisor) ; Fiala, Radek (referee)
There are a number of studies that deal with detection of road network from image Remote Sensing data. However, little work has been done on algorithms for horizontal road signs detection from Remote Sensing data. On the other hand there are many papers that deal with horizontal road signs detection in the field of Computer vision. Theoretical part of master thesis sumarizes the methods that are used to detect objects from both, Remote Sensing and Computer vision data. In the practical part an algorithm of automatic Zebra-crossing detection based on Aerial Images and vector road layer is designed. Zebra-crossings are detected using matching of image with set of predefined patterns. Obtained set of potential objects is then filtred using geometric and relational criteria. At the end of this thesis, the proposed algorithm is validated and the results are discussed with literature. Key words: Zebra-crossing, Horizontal road signs, Image matching, Aerial images
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Possibily GIS methods for documentation of paleontological relics
Čelonk, Marek ; Štefanová, Eva (advisor) ; Potůčková, Markéta (referee)
Possibily GIS methods for documentation of paleontological relics Abstract The bachelor thesis is focused on use of geoinformatic methods for creation of 3D model. The thesis is produced in cooperation with the Chlupáč's Museum of Earth History, which lent a paleontological artifact for processing. The theoretical part deals with laser scanning and close-range photogrammetry. Both methods are used in the practical part for own data colection and subsequent creation of 3D model. Data processing was mostly done in Trimble RealWorks, MeshLab and Agisoft PhotoScan. Another output is the HTML page that allows visualization in the Internet environment. key words 3D model, laser scanning, close-range photogrammetry, point cloud
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Determination of snow water equivalent from microwave radiometer measurements
Klímová, Tereza ; Kolář, Jan (advisor) ; Potůčková, Markéta (referee)
DETERMINATION OF SNOW WATER EQUIVALENT FROM MICROWAVE RADIOMETER MEASUREMENTS Abstract Snow water equivalent ammount of water in snow and its knowledge helps for example in flood prognostication. This bachelor thesis engages with determination of snow water equivalent from microwave radiometer's data in cooperation with data from ground stations. Norway was choosen because of its good data availability. Microwave radiometer AMSR2 on Japanese satellite GCOM has been used as a basic instrument. For map creation with snow water equivalent method considering differences of two spectral canals and other snow attributes were used. During verification of this method maps from Norwegian Meteorological Institute and EUMETSAT which provils different method in map creation were used. keywords: snow water equivalent, remote sensing, microwave radiometer
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Spectroscopic and statistical methods for detailed mapping of vegetation in the Krkonoše Mountains National Park
Minárčik, Miroslav ; Kupková, Lucie (advisor) ; Potůčková, Markéta (referee)
Spectroscopic and statistical methods for detailed mapping of vegetation in the Krkonoše Mountains National Park Abstract The diploma thesis is focused on the detailed classification of vegetation in the Krkonoše Mountains National Park using DCA (Detrended Correspondence Analysis) ordination method in combination with PLSR (Partial Least Square Regression) analysis. The resulting regression analysis values were applied to the hyperspectral imagery (APEX). The classification results were compared to the supervised classification SVM (Support Vector Machine). The DCA method was able to explain 16,3 % variation for the first three axes of the ordination analysis. Subsequent correlation with spectral data of vegetation showed that the highest confidence value reached the first axis correlated with field spectral data (R2 = 0,56). The resulting classification map created using RGB composition showed detailed information on the composition of the vegetation. Keywords: The Krkonoše Mountains National Park, classification, APEX, DCA, PLSR, hyperspectral data
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