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Number of results: 369
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Abstract

In the paper the model of the disturbing potential based on the lower-degree harmonic spherical polynomials and the local density model of topographic masses has been proposed. Topographic masses are represented by DTM. The model parameters are fixed by the use of quasigeoid heights as well as a dense network of gravity points. Preliminary analyses of the model's robustness of gravimetric data errors have also been included.
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Authors and Affiliations

Marek Trojanowicz
ORCID: ORCID
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Abstract

In this paper there are presented results of applying the methods of the time series analysis to the problem of recognizing small boats. It has been showed that the acoustic signals of the boats can be classified by means of clustering algorithms.
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Authors and Affiliations

Marek Przyborski
Andrzej Stateczny
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Abstract

The paper presents such a method of distribution of observations in a surveying network, which allows to meet requirements concerning the network with the possibly lowest direct costs of survey. As a result, a set of azimuths, sides, angles and GPS chords which can be measured in a given network is obtained; then the selection of a subset, which meets the above criteria may be performed. The OPTY98 computer system, which time of calculation may be accepted by an arbitrary network, has been developed for the proposed algorithm. Required data as well as obtained results are presented using the example of the Refe network.
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Authors and Affiliations

Stanisław Lisiewicz
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Abstract

The geodesy literature seems to offer comprehensive insight into the planar Helmert transformation with Hausbrandt corrections. Specialist literature is mainly devoted to the issues of 3D transformation. The determination of the sought values, coordinates in the target system, requires two stages of computations. The classical approach yields ‘new’ coordinates of reference points in the target system that should not be changed in principle. This requires the Hausbrandt corrections. The paper proposes to simplify the two-stage process of planar transformation by assigning adjustment corrections to reference point coordinates in the source system. This approach requires solving the Helmert transformation by adjusting conditioned observations with unknowns. This yielded transformation results consistent with the classical method. The proposed algorithm avoided the issue of correcting the official coordinates of the control network and using additional (post-transformation) corrections for the transformed points. The proposed algorithm for solving the plane Helmert transformation for �� > 2 reference points simplifies the computing stages compared to the classical approach. The assignment of adjustment corrections to coordinates of reference points in the source system helps avoid correcting coordinates of the reference points in the target system and additional corrections for transformed points. The main goal of any data adjustment process with the use of the least squares method is (by definition) obtaining unambiguous quantities that would strictly meet the mathematical relationships between them. Therefore, this work aims to show such a transformation adjusting procedure, so that no additional computational activities related to the correction of already aligned results are necessary.
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Authors and Affiliations

Tadeusz Gargula
1
ORCID: ORCID
Pelagia Gawronek
1
ORCID: ORCID

  1. University of Agriculture in Krakow, Krakow, Poland
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Abstract

The aim of this study was to evaluate millimeter-scale deformations in Tallinn, the capital of Estonia, by using repeated leveling data and the synthetic aperture radar (SAR) images of Sentinel-1 satellite mission. The persistent scattered interferometric SAR (PS-InSAR) analysis of images from ascending and descending orbits from June 2016 to November 2021 resulted the line-of-sight (LOS) displacement velocities in the Tallinn city center. Velocity solutions were estimated for the full period of time, but also for shorter periods to monitor deformation changes in yearly basis. The gridded LOS velocity models were used for the decomposition of east-west and vertical velocities. Additionally, the uncertainty of 2D velocity solutions was estimated by following the propagation of uncertainty. The 3D velocity of permanent GNSS station “MUS2” in Tallinn was used to unify the reference of all PS-InSAR velocity solutions. The results of the latest leveling in Tallinn city center in 2007/2008 and 2019 showed rather small subsidence rates which were in agreement with InSAR long-termsolution. However, the short-termInSAR velocity solutions revealed larger subsidence of city center with a rate about –10 mm/yr in 2016–2017, and the uplift around 5 mm/yr in 2018–2019 with relatively stable periods in 2017–2018 and 2019–2021. The inclusion of groundwater level observation data and the geological mapping information into the analysis revealed possible spatiotemporal correlation between the InSAR results and the groundwater level variations over the deep valleys buried under quaternary sediments.
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Authors and Affiliations

Tõnis Oja
1
ORCID: ORCID
Anti Gruno
1

  1. Datel AS, Tallinn, Estonia

Authors and Affiliations

Jacek Paziewski
1
ORCID: ORCID
Dogan Ugur Sanli
2
ORCID: ORCID

  1. University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
  2. Yildiz Technical University, Istanbul, Turkey
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Abstract

The purpose of this article was to provide the user with information about the number of buildings in the analyzed OpenStreetMap (OSM) dataset in the form of data completeness indicators, namely the standard OSM building areal completeness index (C Index), the numerical completeness index (COUNT Index) and OSM building location accuracy index (TP Index). The official Polish vector database BDOT10k (Database of Topographic Objects) was designated as the reference dataset. Analyses were carried out for Piaseczno County in Poland, differentiated by land cover structure and urbanization level. The results were presented in the form of a bivariate choropleth map with an individually selected class interval suitable for the statistical distribution of the analyzed data. The results confirm that the completeness of OSM buildings close to 100% was obtained mainly in built-up areas. Areas with a commission of OSM buildings were distinguished in terms of area and number of buildings. Lower values of completeness rates were observed in less urbanized areas. The developed methodology for assessing the quality of OSM building data and visualizing the quality results to assist the user in selecting a dataset is universal and can be applied to any OSM polygon features, as well as for peer review of other spatial datasets of comparable thematic scope and detail.
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Authors and Affiliations

Sylwia Borkowska
1
ORCID: ORCID
Elzbieta Bielecka
1
ORCID: ORCID
Krzysztof Pokonieczny
1
ORCID: ORCID

  1. Military University of Technology, Warsaw, Poland
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Abstract

We present a summary of research carried out in 2019–2022 in Poland in the area of general theory and methodology in geodesy. The study contains a description of original contributions by authors affiliated with Polish scientific institutions. It forms part of the national report presented at the 28th General Assembly of the International Union of Geodesy and Geophysics (IUGG) taking place on 11-20 July 2023 in Berlin, Germany. The Polish authors developed their research in the following thematic areas: robust estimation and its applications, prediction problems, cartographic projections, datum transformation problems and geometric geodesy algorithms, optimization and design of geodetic networks, geodetic time series analysis, relativistic effects in GNSS (Global Navigation Satellite System) and precise orbit determination of GNSS satellites. Much has been done on the subject of estimating the reliability of existing algorithms, but also improving them or studying relativistic effects. These studies are a continuation of work carried out over the years, but also they point to new developments in both surveying and geodesy.We hope that the general theory and methodology will continue to be so enthusiastically developed by Polish authors because although it is not an official pillar of geodesy, it is widely applicable to all three pillars of geodesy.
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Authors and Affiliations

Anna Klos
1
ORCID: ORCID
Marcin Ligas
2
ORCID: ORCID
Marek Trojanowicz
3
ORCID: ORCID

  1. Military University of Technology, Warsaw, Poland
  2. AGH University of Science and Technology, Krakow, Poland
  3. Wroclaw University of Environmental and Life Science, Wroclaw, Poland
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Abstract

The aim of this research is to evaluate the performance of four UAV image processing software for the automatic estimation of volumes based on estimated volume accuracy, spatial accuracy, and execution time, with and without Ground Control Points (GCPs). A total of 52 images of a building were captured using a DJI Mavic Air UAV at 60m altitude and 80% forward and side overlap. The dataset was processed with and without GCPs using Pix4DMapper, Agisoft Metashape Pro, Reality Capture, and 3DF Zephyr. The UAV-based estimated volume generated from the software was compared with the true volume of the building generated from its as-built 3D building information modeled in Revit 2018 environment. The resulting percentage difference was computed. The average volumes estimated from the four software with the use of GCPs were 4757.448 m3 (3.87%), 4728.1 m3 (2.54%), 4291.561 m3 (11.5%), and 4154.938 m3 (14.35%), respectively. Similarly, when GCPs were not used for the image processing, average volumes of 4631.385 m3 (4.52%), 4773.025 m3 (1.6%), 4617.899 m3 (4.89%), and 4420.403 m3 (8.92%) were obtained in the same order. In addition to the volume estimation analysis, other parameters, including execution time, positional RMSE, and spatial resolution, were evaluated. Based on these parameters, Agisoft Metashape Pro proved to be more accurate, time-efficient, and reliable for volumetric estimations from UAV images compared to the other investigated software. The findings of this study can guide decision-making in selecting the appropriate software for UAV-based volume estimation in different applications.
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Authors and Affiliations

Oluibukun Gbenga Ajayi
1 2
ORCID: ORCID
Bolaji Saheed Ogundele
2
ORCID: ORCID
Gideon Abidemi Aleji
2
ORCID: ORCID

  1. Namibia University of Science and Technology, Windhoek, Namibia
  2. Federal University of Technology, Minna, Nigeria
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Abstract

The paper presents a concept of application of the RTK-GPS technique to surveys of railway tracks. The concept was examined during an experimental survey performed over a 2 km long track section. The test survey confirmed functionality and sufficient accuracy of the RTK-GPS method as applied to railway track measurements aimed at track regulation.
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Authors and Affiliations

Jan Gocal
Michał Strach
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Abstract

The paper presents discusses a formula for the mean error m, of the refraction factor, determined basing on synchronie and bi-directional observations of vertical angles, performed for a section of trigonometric levelling. It turns out from analysis of the formula that the mean error of this factor is mostly influenced by mean errors of vertical angles and heights of distance meters and prisms over survey points. The error of a distance may be neglected; this leads to the simple working formula.
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Authors and Affiliations

Aleksander Skórczyński
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Abstract

According to analyses of results of surveying measurements, description of undefined subsidence, performed with the use of S. Knothe's model is characterised by the sufficient coherence with results of measurements since the moment when the full subsiding trough becomes visible on the terrain surface. Lower coherence with results of measurements appears in the initial period after commencement of exploitation. In order to improve the quality of description within the initial phase of subsidence, a mathematical model has been developed, which is based on relations between the coefficient of the velocity of subsidence and the time co-ordinate, and from geometric co-ordinates. Obtained solutions have been verified basing on results of surveying measurements, with the use of a special computer software.
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Authors and Affiliations

Piotr Strzałkowski
ORCID: ORCID
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Abstract

One of the basic processes in photogrammetry consists of identification and measurements of conjugate (homologous) points located within image overlapping. In analytical photogrammetry this process is solved manually by an observer. In digital photogrammetry this process is solved automatically by software and it is called image matching. This process has considerable importance for automation of orientation or aerial triangulation of photographs. The accuracy of image matching process influences the accuracy of determination of image orientation elements and computed point coordinates. This article presents the author's idea concerning matching of digital images with regard to correlation between neighbouring pixels. First, the problem of correlation between point co-ordinates will be examined in analytical photogrammetry, what will simplify considerations related to digital photo gram metry.
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Authors and Affiliations

Chinh Ke Luong
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Abstract

The problems of identification of objects have been strictly bound with sea navigation for a long time. The article presents a method of object identification by means of artificial neural networks. The classification of objects is effected on the basis of a radio signal. A comparison between classical methods and neural methods has been made. The results of research performed have been presented on real data, and a detailed analysis of the probabilistic network and its identification.
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Authors and Affiliations

Andrzej Stateczny
Tomasz Praczyk
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Abstract

Climate atlases summarize large sets of quantitative and qualitative data and are results of complex analytical cartographic work. These special geographical publications summarize long term meteorological observations, provide maps and figures which characterise different climate elements. Visual information is supplemented with explanatory texts. A lot of information on short and long term changes of climate elements were provided in published Lithuanian atlases (Atlas of Lithuanian SDR, 1981; Climate Atlas of Lithuania, 2013), as well as in prepared but unpublished Lithuanian Atlas (1989) and in upcoming new national atlas publications (National Atlas of Lithuania. 1 st part, 2014). Climate atlases has to be constantly updated to be relevant and to describe current climate conditions. Comprehensive indicators of Lithuanian climate are provided in different cartographic publications. Different time periods, various data sets and diverse cartographic data analysis tools and visualisation methods were used in these different publications.
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Authors and Affiliations

Donatas Valiukas
Audronė Galvonaitė
Algimantas Česnulevičius
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Abstract

The summary of research activities concerning reference frames and reference networks performed in Poland in a period of 2011–2014 is presented. It contains the results of research on implementation of IUGG2011 and IAU2012 resolutions on reference systems, implementation of the ETRS89 in Poland, operational work of permanent IGS/ EUREF stations in Poland, operational work of ILRS laser ranging station in Poland, active GNSS station networks in Poland, maintenance of vertical control in Poland, maintenance and modernization of gravity control, and maintenance of magnetic control in Poland. The bibliography of the related works is given in references.
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Authors and Affiliations

Jaroslaw Bosy
Jan Krynski
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Abstract

The quarrying industry is changing the local landscape, forming deep open pits and spoil heaps in close proximity to them, especially lignite mines. The impact can include toxic soil material (low pH, heavy metals, oxidations etc.) which is the basis for further reclamation and afforestation. Forests that stand on spoil heaps have very different growth conditions because of the relief (slope, aspect, wind and rainfall shadows, supply of solar energy, etc.) and type of soil that is deposited. Airborne laser scanning (ALS) technology deliver point clouds (XYZ) and derivatives as raster height models (DTM, DSM, nDSM=CHM) which allow the reception of selected 2D and 3D forest parameters (e.g. height, base of the crown, cover, density, volume, biomass, etc). The automation of ALS point cloud processing and integrating the results into GIS helps forest managers to take appropriate decisions on silvicultural treatments in areas with failed plantations (toxic soil, droughts on south-facing slopes; landslides, etc.) or as regular maintenance. The ISOK country-wide project ongoing in Poland will soon deliver ALS point cloud data which can be successfully used for the monitoring and management of many thousands of hectares of destroyed post-industrial areas which according to the law, have to be afforested and transferred back to the State Forest.
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Authors and Affiliations

Paweł Hawryło
Marta Szostak
Piotr Wężyk
Wojciech Krzaklewski
Marek Pająk
Marcin Pierzchalski
Piotr Szwed
Michał Ratajczak
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Abstract

The adjustment problem of the so-called combined (hybrid, integrated) network created with GNSS vectors and terrestrial observations has been the subject of many theoretical and applied works. The network adjustment in various mathematical spaces was considered: in the Cartesian geocentric system on a reference ellipsoid and on a mapping plane. For practical reasons, it often takes a geodetic coordinate system associated with the reference ellipsoid. In this case, the Cartesian GNSS vectors are converted, for example, into geodesic parameters (azimuth and length) on the ellipsoid, but the simple form of converted pseudo-observations are the direct differences of the geodetic coordinates. Unfortunately, such an approach may be essentially distorted by a systematic error resulting from the position error of the GNSS vector, before its projection on the ellipsoid surface. In this paper, an analysis of the impact of this error on the determined measures of geometric ellipsoid elements, including the differences of geodetic coordinates or geodesic parameters is presented. Assuming that the adjustment of a combined network on the ellipsoid shows that the optimal functional approach in relation to the satellite observation, is to create the observational equations directly for the original GNSS Cartesian vector components, writing them directly as a function of the geodetic coordinates (in numerical applications, we use the linearized forms of observational equations with explicitly specified coefficients). While retaining the original character of the Cartesian vector, one avoids any systematic errors that may occur in the conversion of the original GNSS vectors to ellipsoid elements, for example the vector of the geodesic parameters. The problem is theoretically developed and numerically tested. An example of the adjustment of a subnet loaded from the database of reference stations of the ASG-EUPOS system was considered for the preferred functional model of the GNSS observations.
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Authors and Affiliations

Roman Kadaj
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Abstract

Population data are generally provided by state census organisations at the pre- defined census enumeration units. However, these datasets very are often required at user- defined spatial units that differ from the census output levels. A number of population estimation techniques have been developed to address these problems. This article is one of those attempts aimed at improving county level population estimates by using spatial disaggregation models with support of buildings characteristic, derived from national topographic database, and average area of a flat. The experimental gridded population surface was created for Opatów county, sparsely populated rural region located in Central Poland. The method relies on geolocation of population counts in buildings, taking into account the building volume and structural building type and then aggregation the people total in 1 km quadrilateral grid. The overall quality of population distribution surface expressed by the mean of RMSE equals 9 persons, and the MAE equals 0.01. We also discovered that nearly 20% of total county area is unpopulated and 80% of people lived on 33% of the county territory.
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Authors and Affiliations

Beata Calka
Elżbieta Bielecka
Katarzyna Zdunkiewicz
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Abstract

Lexical knowledge sources are indispensable for research, education and general information. The transition of the reference works to the digital world has been a gradual one. This paper discusses the basic principles and structure of knowledge presentation, as well as user access and knowledge acquisition with specific consideration of contributions in German. The ideal reference works of the future should be interactive, optimally adapted to the user, reliable, current and quotable.
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Authors and Affiliations

Wolf Günther Koch
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Abstract

Considering the recent mass movement of people fleeing war and oppression, an analysis of changes in migration, in particular an analysis of the final destination refugees choose, seems to be of utmost importance. Many international organisations like UNHCR (the United Nations High Commissioner for Refugees) or EuroStat gather and provide information on the number of refugees and the routes they follow. What is also needed to study the state of affairs closely is a visual form presenting the rapidly changing situation. An analysis of the problem together with up-to-date statistical data presented in the visual form of a map is essential. This article describes methods of preparing such interactive maps displaying movement of refugees in European Union countries. Those maps would show changes taking place throughout recent years but also the dynamics of the development of the refugee crisis in Europe. The ArcGIS software was applied to make the map accessible on the Internet. Additionally, online sources and newspaper articles were used to present the movement of migrants. The interactive map makes it possible to watch spatial data with an opportunity to navigate within the map window. Because of that it is a clear and convenient tool to visualise such processes as refugee migration in Europe.
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Authors and Affiliations

Beata Calka
Bruce Cahan

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