National Repository of Grey Literature 148 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
A correction of the local incidence angle of SAR data: a land cover specific approach for time series analysis
Paluba, Daniel ; Štych, Přemysl (advisor) ; Mouratidis, Antonios (referee)
To ensure the highest possible temporal resolution of SAR data, it is necessary to use all the available acquisition orbits and paths of a selected area. This can be a challenge in a mountainous terrain, where the side-looking geometry of space-borne SAR satellites in combination with different slope and aspect angles of terrain can strongly affect the backscatter intensity. These errors/noises caused by terrain need to be eliminated. Although there have been methods described in the literature that address this problem, none of these methods is prepared for operable and easily accessible time series analysis in the mountainous areas. This study deals with a land cover-specific local incidence angle (LIA) correction method for time-series analysis of forests in mountainous areas. The methodology is based on the use of a linear relationship between backscatter and LIA, which is calculated for each image separately. Using the combination of CORINE and Hansen Global Forest databases, a wide range of different LIAs for a specific forest type can be generated for each individual image. The algorithm is prepared and tested in cloud-based platform Google Earth Engine (GEE) using Sentinel-1 open access data, SRTM digital elevation model, and CORINE and Hansen Global Forest databases. The method was tested...
Černický, David ; Štych, Přemysl (advisor) ; Laštovička, Josef (referee)
This thesis deals with factors influencing the average speed on Czech roads. Curvature and inclination of the slopes were selected among the main factors influencing the average speed. Until now, these factors have been considered at discrete intervals, not as continuous functions. The function for calculating the curvature is based on ČSN 73 6101, where the equation with all variables is directly defined. The functional relationship for the movement of vehicles in sloping terrain was created from data from scientific articles. Therefore, an algorithm was implemented in this thesis, which can automatically evaluate the average speed on the road network. Python was used to implement this algorithm. Furthermore, there is a testing section for travel times, which is validated using route planners and also supported by extensive field research. Testing took place in GIS using network analysis methods. Testing has shown that the inclusion of curvature and inclination will significantly improve the calculation of travel times. key words: network analyst, curvature, gis, algorithm
Evaluation of forest vegetation based on time series of remote sensing data
Laštovička, Josef ; Štych, Přemysl (advisor) ; Brom, Jakub (referee) ; Bucha, Tomáš (referee)
Příloha k disertační práci: Abstrakt v AJ (Mgr. Josef Laštovička) Abstract This dissertation thesis deals with the study of forest ecosystems in the central Europe with the time series of multispectral optical satellite data. These forest ecosystems have been influenced by biotic and abiotic disturbances for the last decade. The time series of the satellite data with high spatial resolution allow the detection and analysis of forest disturbances. This thesis is mainly focused primally on free available Landsat and Sentinel-2 data, these two data types were compared. From methods, the difference time series analyses / algorithms were used. The whole thesis can be divided into two main parts. The first one analyses usability of classifiers for detection of forest ecosystems with per-pixel and sub-pixel methods. Specifically, the Neural Network, the Support Vector Machine and the Maximum Likelihood per-pixel classifiers were used and compared for different types of data (for data with high spatial resolution - Landsat or Sentinel-2; very high spatial resolution - WorldView-2) and for classification of protected forest areas. The Support Vector Machine were selected as the most suitable method for forest classifications (with most accurate outputs) from the list of selected per-pixel classifiers. Also, Spectral...
Use of contemporary 3D geoinformation technologies for historical reconstructions of sites: case study Zahrádka u Ledče nad Sázavou
Berka, Rostislav ; Laštovička, Josef (advisor) ; Štych, Přemysl (referee)
Use of contemporary 3D geoinformation technologies for historical reconstructions of sites: case study Zahrádka u Ledče nad Sázavou Abstract This bachelor thesis deals with contemporary 3D GIS technologies and methods used for historical reconstructions, especially reconstructions of lost sites and objects. Thesis contains an overview of technologies, methods and softwares suitable for these purposes. Thesis is focused on quite unique single image-based modeling, which uses geometry of object in the image. There is also brief overview of visualisation 3D models on the internet and web mapping. Thesis introduces a prescription for creating 3D model of lost site. First, TIN is produced from contours of old maps and DMR 5G data using breaklines, which are generated automatically. SFM models of preserved objects and models of destroyed objects acquired through single image-based modeling with help of old archival images, are placed on DTM. The case study area is the lost town of Zahrádka u Ledče nad Sázavou. The results of this work are view scenes and interactive web map aplication for visualisation of 3D model. The accuracy of used single image-based modeling method is compared to the standard SFM technique. SFM had better accuracy. Keywords: 3D model, 3D GIS, single image-based modeling using geometric...
Mór, Jiří ; Kupková, Lucie (advisor) ; Štych, Přemysl (referee)
This thesis deals with land use and land cover changes in two geographically close areas - - "Milovicko" and "Rožďalovicko". The thesis's main goal was to analyze land use / land cover changes between years 1836 and 2019 in the surroundings of Milovice town, where the military area called "Milovice - Mladá" was established in 1904 and dissolved in 1991, and in intensively-used agricultural area around small town Rožďalovice. The evaluation was mainly based on vectorized maps of so called Stable cadastre and on the data of current cadastre. Another goal was to analyze the development of landscape structure in surroundings of Rožďalovice, also between years 1836 and 2019. We aimed also to answer the question, if parcels of arable land in the stable cadastre could be considered as patches in the landscape mosaic. Based on three types of satellite data (PlanetScope, Sentinel-2 and Landsat 8) it was analyzed, how much landscape metrics and a description of landscape structure change in dependency on spatial resolution of remote sensing data. Satellite images from June 2019 were classified and then the landscape metrics, which characterized landscape structure, were calculated. Development of land use in Milovice surroundings differs from the trends of development of other (post)military areas as classes...
Spatial disaggregation of population data using 3D city model
Kovačka, Vít ; Brůha, Lukáš (advisor) ; Štych, Přemysl (referee)
The thesis studies the use of existing 3D models as a source of information about the volume of buildings, which is further used in statistical modeling of spatial data. Existing approaches to the spatial data disaggregation are presented, including those utilizing three- dimensional data. The method of obtaining volume information is implemented employing ArcPy libraries for multipatch format. Open source PostgreSQL PostGIS database functions were put in use to retrieve the volumes from rasters containing information about the height of the building. Disaggregation, performed with both 2D and 3D data, is evaluated in terms of accuracy, model performance, and the ability of 3D data to replace some 2D data. The proposed calculation methods and model results are critically evaluated. Keywords: 3D data, volume, Prague, disaggregation, modeling, ArcPy, PostGIS, machine learning
Updating of land use cadastral records using satellite data Sentinel-2
Šaffová, Michaela ; Štych, Přemysl (advisor) ; Kupková, Lucie (referee)
Updating of land use cadastral records using satellite data Sentinel-2 Abstract The aim of the project is to propose a methodical procedure which will classify selected land use classes with an accuracy of more than 80 %. Constructed methodical procedure will have the task of detecting the discrepancy of land reported in the cadastral records with the real state in the landscape identified by satellite Sentinel-2 data classification. Classification of agricultural land classes (arable land, permanent grassland, orchard and vineyards) is solved in this project using multitemporal data Sentinel-2 using object classification methods. The first part of thesis focuses on the literary introduction to the topic of the theme. The second part is devoted to the process of creating a methodical procedure for object classification of land use classes, where parameters are defined by experimental activity and thresholds of the defined classification. The results of the work are compared and evaluated using the overall accuracy and error matrices of the classification using the developed algorithm. Keywords: cadastral records, multitemporal satellite imagery, object-base classification, Sentinel-2, agricultural land resources
Temperature characteristics of surface using remote sensing methods
Hofrajtr, Martin ; Štych, Přemysl (advisor) ; Brom, Jakub (referee)
Temperature characteristics of surface using remote sensing methods Abstract The aim of this thesis is to design a methodology for refining the land surface temperature values obtained from Landsat 8 satellite data in areas with diverse land cover. The research section describes factors influencing the radiation of the Earth's surface. Also mentioned are current methods used for processing infrared thermal data and calculate land surface temperature. The practical part describes satellite and airborne data used in the analytical and verification process. All parts of the applied method leading to the subpixel value of the land surface temperature are described in detail in the method part. The results are then compared with airborne verification data with better spatial resolution and with currently used methods. Finally, the pros and cons of this method and its possible improvement in the future are mentioned. Key words: land surface temperature, land surface emissivity, satellite data, Landsat 8, airborne data, subpixel method, Czech Republic
Use of current and historical geospatial data for 3d modeling of hradec králové in different time periods
Šrollerů, Alex ; Laštovička, Josef (advisor) ; Štych, Přemysl (referee)
Use of current and historical geospatial data for 3D modeling of Hradec Králové in different time periods Abstract This bachelor's thesis is mainly focused on historical and current geospatial data and the basics of three-dimensional city modeling. It provides an overview on basic methods, data and software suitable for 3D city modeling in different time periods and possibilities of 3D visualization. The practical part describes the process of creating a 3D model in different time periods, namely the cadastral area of Hradec Králové in the years 1840, 1912, 1952 and present. The model consists of terrain interpolated from ZABAGED contour lines and buildings extruded from vector footprints. Subsequent manual modeling took place in SketchUp CAD software. Historical large-scale maps, contemporary orthophoto and OSM are used for this task. The model is visualized using flyby animations, view scenes, interactive browser and presented on a self-created web page and StoryMap JS. Keywords: 3D model, SketchUp, buildings, DTM, historical data.
Normalization of Time Series Data of Landsat
Svoboda, Jan ; Štych, Přemysl (advisor) ; Kolář, Jan (referee)
Spectral reflectance of the Earth surface, obtained from the satellite images, should be independent from the external influences and should reflect the surface properties, specifically the proportion of the radiance reflected from the object. It was proved in this paper that the time series of the 63 images from the Landsat 5 satellite were visibly influenced by the external factors even in the case of the images already atmospherically corrected. These external factors were age of the image and WRS-2 position from which the image was obtained. Age of the image was documented with the steady decrease of the spectral reflectance values of the invariant features, especially in the visible part of the electromagnetic spectrum, caused by the sensor degradation. The influence of the WRS-2 position was documented especially in the infrared bands. The western parts of the images are lighter (have higher values of the surface reflectance) than the eastern parts. That may cause the difference between values when monitoring one spot in two overlapping WRS-2 positions. The method originally used for the relative radiometric normalization IR-MAD was here applied to normalize the surface reflectance data, and resulted in the fact that these influences did not show up any more. In order to extend the time...

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