|
| |
|
|
Detection of anthropogenic terrain features in the summit area of the Luční and Studniční hora mountains (Krkonoše) with use of airborne laser scanning data
Krusová, Anna ; Lysák, Jakub (advisor) ; Potůčková, Markéta (referee)
The thesis focuses on detection of micrographic features using airborne laser scanning data. The aim of the thesis is to propose a novel method for detecting terrain features and to identify and describe terrain objects corresponding to anthropogenic interventions in the arctic-alpine tundra region in the summit area of the Luční and Studniční hora mountains in the Krkonoše Mountains. Based on existing studies, a new detection method of specific micrographic features was proposed by combining two types of data, i.e. point cloud and its raster representation. Initially, polygon approximations of terrain objects were derived from a digital terrain model, and their spatial delineation was further refined locally using point clouds. The output provides the most complete and accurate polygon delineation of the terrain features to date, considering the available data, the specific characteristics of the area, and in comparison to previously conducted studies. The proposed algorithm has identified hundreds of additional terrain features compared to the reference data. However, this number includes false positive features, which need to be manually eliminated. Key words: airborne laser scanning, micrographic features detection, archaeological prospection, digital terrain model, local relief model, Krkonoše...
|
|
|
Geometric Aspects of Detecting Grassland Mowing in Krkonoše Mountains Based on Sentinel-1 Coherence
Dvořák, Jakub ; Potůčková, Markéta (advisor) ; Mouratidis, Antonios (referee)
Grassland mowing is a common management practice used in European grasslands for livestock fodder production and to enhance biodiversity. To support a less intensive use of grasslands, public agencies look for a reliable way to monitor the management performed on the grasslands. Satellite remote sensing is a key tool for monitoring over large areas, with SAR remote sensing being especially useful in areas with high cloud cover. However, grassland monitoring using SAR in complex terrain is not fully understood and may come with challenges related to topography and sensor geometry. To explore these potential challenges, this thesis detected mowing events using a high-resolution DEM for precise coregistration and terrain correction of Sentinel-1 SAR imagery. Effect of local incidence angle on detection accuracy from interferometric coherence was also explored. The hypotheses were tested on 61 grassland plots in Krkonoše mountains, Czechia. Detection accuracies in this thesis were higher than in previous studies when only considering SAR detections. The improvement was most likely caused by counting detections from individual orbits to assess the certainty of each detection. A deeper analysis showed that using a high-resolution DEM led to a horizontal shift in computed coherence, but the shift had no...
|
|
|
Topographic model of the archeological site Stradonice based on UAV LiDAR point cloud
Prýmek, Jan ; Potůčková, Markéta (advisor) ; Hodač, Jindřich (referee)
The bachelor thesis is focused on the creation of a topographic model of the burial mound near Stradonice. The aim of the work was to filter LiDAR point clouds acquired from an UAV and aircraft platforms over the forested terrain of the area of interest, to analyze them in terms of point density corresponding to the relief and vegetation, to compare visual and automated detection of archaeological objects and to verify the results by field survey. The theoretical part describes the principle of laser scanning, its use in archaeology and the application of automated detection approaches to archaeological objects. Furthermore, the development of barrow burials from the Eneolithic to the Middle Ages is outlined and the area of interest is described in detail. The mound burial site at Stradonice is divided into two parts located not far from each other, which are probably not very closely related. In one part there are both rectangular barrows placed in rows and circular ones which occur irregularly around them as if they were of a different age. In the other part, there are only mounds with a circular plan, and some of them are arranged regularly. In the practical part, three sets of point clouds were processed, two of their own from UAVs and one from an aircraft provided by the ČÚZK. Vegetation was...
|
|
|
CRISM sensor - available data and possible applications for mineral detection on Mars
Pavlová, Martina ; Červená, Lucie (advisor) ; Potůčková, Markéta (referee)
This bachelor's thesis focuses on data accumulated by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) sensor and the possibilities of their subsequent processing. The first part of this paper focuses on the history of remote sensing of Mars since its beginning in the 1960s, with the most detailed description of the Mars Reconnaissance Orbiter (MRO) mission which carries the CRISM spectroradiometer. The nine different data products acquired by this instrument are described in detail together with the possibilities of their download and subsequent processing. Furthermore, the minerals found on the surface of Mars are mentioned and examples of their spectral curves are shown. In the practical part, the processing of CRISM data in JCAT is first presented, from the actual data download to the creation of spectral curves suitable for comparison with spectral libraries. Subsequently, an image containing low calcium pyroxene was selected. This image was preprocessed in CAT in ENVI and using three different methods which were Linear Spectral Unmixing (LSU), Spectral Angle Mapper (SAM) and spectral parameter calculation, the detection of the selected mineral was performed. The LSU and SAM methods gave similar results, but the calculation of spectral parameters differed more from them, which...
|
|
|
Remote Sensing of the Icy Moons of Jupiter - Galileo mission
Tomášková, Eliška ; Červená, Lucie (advisor) ; Potůčková, Markéta (referee)
The bachelor's thesis focuses on the processing and analysis of Galileo SSI and NIMS image data, which captures the Tyre region of Europa and the Kittu region of Ganymede. Initially, the problems of data retrieval from the PDS archive and its thorough radiometric and geometric corrections are addressed. Pre-processing, visualization, and subsequent data analysis were conducted using the POW tool, ISIS3, ENVI, and ArcGIS Pro software. Based on the principal component analysis of the NIMS data, the two most different end-members representing ice and "salt" were selected. These were then used in Linear Spectral Unmixing, which provided information on the spatial distribution and relative concentrations of the "salt" end-member in the study areas. The outputs from the hyperspectral data were projected over the higher spatial resolution data to examine relationships between surface morphology and composition. The resulting SSI, Voyager, and NIMS composites suggest a strong correlation between the salt component and areas with disrupted ice crust on Jupiter's icy moons. Furthermore, unsupervised classification of SSI images capturing the Tyre crater was performed and showed similar results to Linear Spectral Unmixing of the NIMS data. Additionally, significant differences in reflectance values between...
|
|
|
Forest monitoring using the GEDI sensor
Šedová, Adéla ; Potůčková, Markéta (advisor) ; Moudrý, Vítězslav (referee)
The overall objective of this thesis was to explore the use of GEDI and its integration with Airborne Laser Scanning (ALS) for large scale forest monitoring. The study was carried out using a sample of GEDI footprints that fell into the timeline of three available ALS datasets that were acquired during the same year. The study area, located in Southeast of Czechia, is covered with mature 121-year-old forest monoculture of Norway spruce (Picea abies), and due to frequent disturbances caused by infestation is closely monitored as a part of research on forest dynamic. As a result, the forest is highly fragmented, and due to its dynamic character, close dates of acquisitions were preferred to a larger dataset. Canopy gaps and low tree densities are known to pose a challenge for large-footprint full-waveform LiDARs. The specific of GEDI sensor, such as its footprint size, were specially designed to overcome these challenges. The options of optimising GEDI's geolocation accuracy were explored. A tool for integrating GEDI and ALS data, the GEDI Simulator, was used to standardise both data sources and derive elevation height, Relative Height (RH) and Canopy Cover Fraction (CCF). The metrics were derived from real GEDI waveforms, simulated GEDI-like waveforms, and calculated from the ALS point cloud, and...
|
|
|
Analysis of tundra vegetation developement using a time series of ortoimages in the Krkonoše Mountains
Pajmová, Petra ; Kupková, Lucie (advisor) ; Potůčková, Markéta (referee)
Analysis of tundra vegetation developement using a time series of ortoimages in the Krkonoše Mountains Abstract The aim of this study is to analyse changes in arctic-alpine tundra vegetation in the Krkonoše Mountains using archival and current aerial imagery with red, green and blue bands and spatial resolution of 0.5 m. Three small areas of interest (cca 100 100 m) with different types of vegetation and a one larger area of the eastern tundra were studied. Several classification methods (Maximum likelihood classification, Random forest and object-based classification) were tested to obtain the best classification results. For more detailed analysis of grass species development, unsupervised classification and extended time series (5 orthoimages) were used for the area of Bílá louka. Classification were executed in softwares ENVI 5.5 and R 4.2.1. The highest overall accuracy of the 2020 image classifications were over 70% in all study areas, in some cases over 80%. With the exception of the Luční hora area (58%), the best overall accuracies for 2004 image were above 65%. After comparing classification results between years 2004 and 2020, a possible development trend was revealed. But due to low accuracy of the 2004 data classifications, this cannot be reliably demonstrated. Key words: classification,...
|
|
|
Detection options of drenage and ameliorate channels using remote sensing data
Čermák, Jan ; Potůčková, Markéta (advisor) ; Štych, Přemysl (referee)
The purpose of this work is to explore detection options of subsurface drainage systems using remote sensing data. Drainage drains soggy soil and increases its fertility, but also allows transport of nutrients such as nitrogen and phosporus into waterways. Location of drainage systems is often unknown because of missing or inacurrate project documentation. Theoretical part is mostly devoted to the description of remote and ground methods of drainage detection. Then objectives of the work are solved. Drainage indications are described in specialized aerial photographs of visible and infrared part of the spectrum. These indications are compared with historical project plans. Methods aimed to improve indication of drainage including Laplacian filter and NDVI are applied and evaluated. Main output is binary raster expressing location of drains. Accuracy of results is evaluated in relation to vectorized indication of drainage from the source images.
|
|
|
Evaluation of influence of interpolation methods on coregistration of radar images
Slačíková, Jana ; Potůčková, Markéta (advisor) ; Hlaváčová, Ivana (referee)
Evaluation of influence of interpolation methods on coregistration of radar images Abstract SAR interferogram processing requires subpixel coregistration of SAR image pair for accurate phase differencing. Errors in alignment introduce phase noise in SAR interferogram. Last step in coregistration is resampling one of SAR images. Also this step introduces errors in SAR interferogram. The resampling algorithms Nearest Neighbor, Bilinear interpolation, Cubic Convolution and advanced methods such as Raised Cosine kernel, Knab interpolation kernel and Truncated Sinc were tested on ERS tandem data and compared. The results were compared with the theory and simulations of earlier investigations (Hanssen, Bamler, 1999), (Migliaccio, Bruno, 2003) and (Cho ... [et al.], 2005). The main experiment in this work was to examine and compare resampling methods on real data to evaluate their effect on the interferometric phase quality and DEM generation. The coregistration performance was evaluated by the coherence (Touzi ... [et al.], 1999) and the sum of phase differences (Li ... [et al.], 2004). No evidence showed that computationally intensive algorithms produced better quality of interferogram than Cubic Convolution. The possibilities of evaluating by means of the accuracy of the final InSAR DEM (Li, Bethel, 2008) were...
|
guest ::
RSS feed.