Search
dr inż. Marek Kulawiak
Employment
- Assistant professor at Department of Geoinformatics
Publications
Filters
total: 22
Catalog Publications
Year 2024
-
Comparison of 3D Point Cloud Completion Networks for High Altitude Lidar Scans of Buildings
PublicationHigh altitude lidar scans allow for rapid acquisition of big spatial data representing entire city blocks. Unfortunately, the raw point clouds acquired by this method are largely incomplete due to object occlusions and restrictions in scanning angles and sensor resolution, which can negatively affect the obtained results. In recent years, many new solutions for 3D point cloud completion have been created and tested on various objects;...
-
UAV-Based Hyperspectral Ultraviolet-Visible Interpolated Reflectance Images for Remote Sensing of Leaf Area Index
PublicationDespite its relation to a number of environmental parameters, ultraviolet (UV) reflectance is rarely used in remote sensing. In this study, we investigate the applicability of UV-vis reflectance for vegetation monitoring with unmanned aerial vehicles (UAV). We measure point reflectance over the study area using a UAV-borne spectrometer, project the points onto the Earth's surface, and interpolate them to obtain continuous reflectance...
Year 2023
-
Study of various machine learning approaches for Sentinel-2 derived bathymetry
PublicationIn recent years precise and up-to-date information regarding seabed depth has become more and more important for companies and institutions that operate on coastlines. While direct, in-situ measurements are performed regularly, they are expensive, time-consuming and impractical to be performed in short time intervals. At the same time, an ever-increasing amount of satellite imaging data becomes available. With these images, it...
-
Validation of Interpolation Algorithms for Multiscale UV-VIS Imaging Using UAV Spectrometer
PublicationIn this study, we present a comparison of popular methods for the interpolation of irregular spatial data in order to determine the applicability of each algorithm for hyperspectral reflectance estimation. The algorithms were benchmarked against a very high-resolution orthoimage from an RGB camera and medium-resolution satellite imagery from Sentinel-2A. We tested five interpolation algorithms: Triangulated Irregular Network (TIN),...
Year 2022
-
A Cost-Effective Method for Reconstructing City-Building 3D Models from Sparse Lidar Point Clouds
PublicationThe recent popularization of airborne lidar scanners has provided a steady source of point cloud datasets containing the altitudes of bare earth surface and vegetation features as well as man-made structures. In contrast to terrestrial lidar, which produces dense point clouds of small areas, airborne laser sensors usually deliver sparse datasets that cover large municipalities. The latter are very useful in constructing digital...
Year 2020
-
GEOINFORMATYCZNE NARZĘDZIE DO BADANIA ZASIĘGU LOKALNYCH STACJI NADAWCZYCH RADIOFONII CYFROWEJ DAB+
PublicationKwestia zapewnienia odpowiedniego pokrycia sygnałem multipleksu jest kluczowym aspektem zarówno dla nadawców publicznych jak i prywatnych, a w szczególności lokalnych stacji zainteresowanych procesem cyfryzacji. W pracy przedstawiono geoinformatyczne narzędzie, umożliwiające badanie zasięgu lokalnych stacji nadawczych radiofonii cyfrowej DAB+. Analizę przeprowadzono dla pionierskiej w Polsce stacji LocalDAB we Wrocławiu. Wyniki...
-
Geospatial Coverage and Signal Quality Measurements of Terrestrial DAB+ Network in Northern Poland
PublicationModern signal coverage maps are prepared based on industry-standard radio propagation models, which take into account a number of parameters, including: type of antenna, distance from the transmitter, type of terrain, etc. However, such simulations are prone to location-specific inaccuracies, and should be verified with in-situ measurements. This paper presents results of a field test of a terrestrial DAB+ (Digital Audio Broadcasting...
-
Improving the Accuracy of Automatic Reconstruction of 3D Complex Buildings Models from Airborne Lidar Point Clouds
PublicationDue to high requirements of variety of 3D spatial data applications with respect to data amount and quality, automatized, effcient and reliable data acquisition and preprocessing methods are needed. The use of photogrammetry techniques—as well as the light detection and ranging (LiDAR) automatic scanners—are among attractive solutions. However, measurement data are in the form of unorganized point clouds, usually requiring transformation...
Year 2019
-
Integration, Processing and Dissemination of LiDAR Data in a 3D Web-GIS
PublicationThe rapid increase in applications of Light Detection and Ranging (LiDAR) scanners, followed by the development of various methods that are dedicated for survey data processing, visualization, and dissemination constituted the need of new open standards for storage and online distribution of collected three-dimensional data. However, over a decade of research in the area has resulted in a number of incompatible solutions that offer...
-
Przetwarzanie hydroakustycznych i lidarowych danych przestrzennych w celu konstrukcji trójwymiarowych modeli rzeczywistych obiektów
PublicationZautomatyzowana rekonstrukcja kształtu powierzchni reprezentowanych przez chmury punktów jest zagadnieniem badanym od wielu lat, jednak rezultaty osiągane za pomocą istniejących algorytmów odtwarzania modeli są dalekie od satysfakcjonujących, jeżeli wejściowe zbiory punktów cechują się nieregularną strukturą przestrzenną, co jest częstym zjawiskiem w przypadku danych pochodzących z sondowania hydroakustycznego czy skaningu laserowego....
Year 2018
-
3D Object Shape Reconstruction from Underwater Multibeam Data and Over Ground Lidar Scanning
PublicationThe technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation,...
-
DAB+ Coverage Analysis: a New Look at Network Planning using GIS Tools
PublicationFor many years, the matter of designing a transmitter network, optimized for best signal coverage, has been a subject of intense research. In the last decade, numerous researchers and institutions used GIS and spatial analysis tools for network planning, especially transmitter location. Currently, many existing systems operate in a strictly two-dimensional manner, not taking into account the three-dimensional nature of the analyzed...
-
Processing of Hydroacoustic and LiDAR Data for Three-dimensional Surface Reconstruction
PublicationThe technologies of sonar and laser scanning are commonly used for obtaining spatial information about underwater and over ground environments in the form of point clouds. Since this data model has known disadvantages, a more practical solution of visualising such data involves the creation of solid three-dimensional meshes composed of edges and facets. In this paper, several methods for 3D shape reconstruction of data obtained...
-
Programmatic Simulation of Laser Scanning Products
PublicationThe technology of laser scanning is widely used for producing three-dimensional digital representations of geographic features. The measurement results are usually available in the form of 3D point clouds, which are often used as a transitional data model in various remote sensing applications. Unfortunately, while the costs of Light Detection And Ranging scanners have dropped significantly in recent years, they are still considered...
Year 2017
-
Multibeam data processing for 3D object shape reconstruction
PublicationThe technology of hydroacoustic scanning offers an efficient and widely-used source of geospatial information regarding underwater environments, providing measurement data which usually have the structure of irregular groups of points known as point clouds. Since this data model has known disadvantages, a different form of representation based on representing surfaces with simple geometric structures, such as edges and facets,...
Year 2016
-
Application of Web-GIS for Dissemination and 3D Visualization of Large-Volume LiDAR Data
PublicationThe increasing number of digital data sources, which allow for semi-automatic collection and storage of information regarding various aspects of life has recently granted a considerable rise in popularity to the term “Big data”. As far as geospatial data is concerned, one of the major sources of Big data are Light Detection And Ranging (LiDAR) scanners, which produce high resolution three-dimensional data on a local scale. The...
-
Methods for quality improvement of multibeam and LiDAR point cloud data in the context of 3D surface reconstruction
PublicationPoint cloud dataset is the transitional data model used in several marine and land remote-sensing applications. During further steps of processing, the transformation of point cloud spatial data to more complex models containing higher order geometric structures like edges and facets may be possible, if an appropriate quality level of input data is provided. Point cloud datasets usually contain a considerable amount of undesirable...
-
Processing of LiDAR and Multibeam Sonar Point Cloud Data for 3D Surface and Object Shape Reconstruction
PublicationUnorganised point cloud dataset, as a transitional data model in several applications, usually contains a considerable amount of undesirable irregularities, such as strong variability of local point density, missing data, overlapping points and noise caused by scattering characteristics of the environment. For these reasons, further processing of such data, e.g. for construction of higher order geometric models of the topography...
-
Web-based 3D processing and dissemination of multibeam sonar data
PublicationThe continuous detailed surveys of the various water bodies over time produce a large and ever-increasing volume and density of underwater sounding data. Three-dimensional data, such as those obtained by multibeam sonar systems, are quite complex to manage, and thus their growing numbers increase the pressure on development of new solutions dedicated to processing them. This paper presents a concept system for web-based dissemination...
Year 2015
-
Reconstruction Methods for 3D Underwater Objects Using Point Cloud Data
PublicationExisting methods for visualizing underwater objects in three dimensions are usually based on displaying the imaged objects either as unorganised point sets or in the form of edges connecting the points in a trivial way. To allow the researcher to recognise more details and characteristic features of an investigated object, the visualization quality may be improved by transforming the unordered point clouds into higher order structures....
Year 2014
-
3D Imaging Of Underwater Objects Using Multi-Beam Data
PublicationOne of the main applications of multibeam sonars is high resolution bathymetry measurement, as well as detecting and imaging of underwater objects like shipwrecks. In order to obtain the visualisation quality good enough to allow the researcher to investigate an object in more detail, the approach relying on construction of three-dimensional model of an imaged object, e.g. consisting of nodes, edges and plane elements (facets)...
-
Three-dimensional Web Geographic Information System using web-based technologies
PublicationWeb-based Geographic Information Systems offer a way of delivering geographic information to devices with small computational power, such as smartphones. In recent years, the rapid development of the Web Graphics Library (WebGL) made it possible to create rich interactive applications running inside a web browser and displaying three-dimensional objects using hardware acceleration. This paper presents a three-dimensional Web-GIS...
seen 1918 times