Satellite-based positioning, which started being developed in the mid-1960s for military purposes, is now used in almost every area. For the studies single and/or double frequency receivers are used. The cost of a receiver and antenna couple that have capable of high coordinate accuracies ranges from $3000 to $15000. With the production of Original Equipment Manufacturer (OEM) receivers, the cost of satellite-based location determination decreases to approximately one in 10 for the civilian user compared to the operations performed with geodetic receivers and antennas. However, although these receivers collect data in multi-Global Navigation Satellite System (GNSS) and frequencies, the accuracy of the coordinate values estimated is not as high as geodetic receivers and antennas. Therefore, it is necessary to carry out an accuracy study to obtain information about which studies can be used in. In this study, measurements were made at the UZEL point located on the roof of the Yıldız Technical University Geomatics Engineering Department by using the ZED-F9P-02B OEM multi GNSS receiver and ANN-MB L1/L2 multi-band GNSS patch antenna. The performance of the test results has been examined by comparing the results from CSRS(Canadian Spatial Reference System)-PPP with the coordinates of the UZEL point. As a result of the comparison, the difference between the coordinate determined with collected 3.5 hr data and the coordinates of the UZEL point has been determined as – 1.4 cm, 2.8 cm, and 9.3 cm in the East, North, and Height directions, respectively

The research investigates the possibility of applying Sentinel-2, PlanetScope satellite imageries, and LiDAR data for automation of land cover mapping and 3D vegetation characteristics in post-agricultural areas, mainly in the aspect of detection and monitoring of the secondary forest succession. The study was performed for the tested area in the Biskupice district (South of Poland), as an example of an uncontrolled forest succession process occurring on post-agricultural lands. The areas of interest were parcels where agricultural use has been abandoned and forest succession has progressed. This paper indicates the possibility of automating the process of monitoring wooded and shrubby areas developing in post-agricultural areas with the help of modern geodata and geoinformation methods. It was verified whether the processing of Sentinel-2, PlanetScope imageries allows for reliable land cover classification as an identification forest succession area. The airborne laser scanning (ALS) data were used for deriving detailed information about the forest succession process. Using the ALS point clouds vegetation parameters i.e., height and canopy cover were determined and presented as raster maps, histograms, or profiles. In the presented study Sentinel-2, PlanetScope imageries, and ALS data processing showed a significant differentiation of the spatial structure of vegetation. These differences are visible in the surface size (2D) and the vertical vegetation structure (3D).

With the developing technology and increasing construction, the importance of structural observations, which are of great significance in disaster management, has increased. Geodetic methods have been preferred in recent years due to their high accuracy and ease of use in Structural Health Monitoring (SHM) Surveys. In this study, harmonic oscillation tests have been carried out on a shake table to determine the usability of the Single Base and the Network Real-Time Kinematic (RTK) Global Navigation Satellite Systems (GNSS) method in SHM studies. It is aimed to determine the harmonic movements of different amplitudes and frequencies created by the shake table with 20 Hz multi-GNSS equipment. The amplitude and frequency values of the movements created using Fast Fourier Transform (FFT) and Time Series Analysis have been calculated. The precision of the analysis results has been determined by comparing the LVDT (Linear Variable Differential Transformer) data, which is the position sensor of the shake table, with the GNSS data. The advantages of the two RTK methods over each other have been determined using the calculated amplitude and frequency differences. As a result of all experiments, it has been determined that network and single base RTK GNSS methods effectively monitor structural behaviours and natural frequencies.

The paper discusses the mode of land acquisition for public road development resulting from the process of land severance performed at the request of the owner in terms of: the legitimacy of land acquisition by the State Treasury or local government units, by virtue of law, upon the land severance approval, the compensation for taking over the land severed for roads, the possibility of restitution of partially acquired plots of land in case a road has not been constructed, and therefore the redundancy of land earmarked for public purposes. The author compares land acquisition procedures set out in historical and currently applicable regulations as well as obligation to pay compensation. The aim of the research is to answer the question of whether the regulations according to which the land allocated for roads is acquired by operation of law by public entities should be modified, and if so, to what extent. On the example of a selected city, research was carried out to determine whether the acquired land is used at a later stage for road construction and what is the scale of compensation claims paid by the municipality. The conducted research made it possible to propose solutions to modify the mode of land severance resulting in land being severed for road development, considering both rational property management and the rights of former owners for restitution in the event public entities failed to use this real property for public purposes.

This study discusses how to model the noise in a Gravity Recovery and Climate Experiment (GRACE)-Mascon derived Equivalent Water Thicknesses (EWT) time-series. GRACE has provided unique information for monitoring variations in EWT of continents in regional or basin scale since 2002. To analyze a GRACE EWT time-series, a standard harmonic regression model is used, but usually assuming white noise-only stochastic model. However, like almost all kinds of geodetic time-series, it has been shown that the GRACE EWT time-series contains temporal correlations causing colored noise in the data. As well known in geodetic modelling studies, neglecting these correlations leads to underestimating the uncertainties, and so misinterpreting the significancy of the parameter estimates such as trend rate, amplitudes of signals etc. In this study, autoregressive noise modeling, which has some advantageous compared to the approaches and methods frequently applied in geodetic studies, is considered for GRACE EWT time series. For this aim, three important basins, namely theYangtze, Murray–Darling and Amazon basins have been examined. Among some applied autoregressive models, the ARMA(1,1) model is obtained as the best-fitting noise model for analyzing the EWT changes in each basin. The obtained results are discussed in terms of forecasting, significancy and consistency with GRACE-FO mission.

Destructive aftershocks such as the M w 7.2 Van earthquake on October 23, 2011, and the Hoy (Iran) earthquake with M w 5.9 on February 23, 2020, occurred in the province of Van and its surroundings. In earthquake studies, the issue of examining the distribution and homogeneity of earthquake incidences with Geographic Information Systems (GIS) based via spatial autocorrelation techniques is frequently investigated. Van province and its surroundings are among the areas with high earthquake risk due to its location on the East Anatolian Compressive Tectonic Block. The aim of this study is to analyze the spatial patterns of earthquakes with magnitude M w 4 and above that occurred in the province of Van and its surroundings during the instrumental period and to determine to cluster. Spatial cluster analyses play an important role in examining the distribution of seismicity. The data used in the study have been taken from the database system of the Earthquake Department of the Republic of Turkey Ministry of Interior Disaster and Emergency Management Presidency. Moran’s I and Getis-Ord Gi methods from spatial autocorrelation techniques were preferred on the earthquake data set to be used in this research. It has aimed to determine the dangerous areas by testing the earthquake distributions in clustered regions via spatial autocorrelation techniques.

3D maps are becoming more and more popular due not only to their accessibility and clarity of reception, but above all, they provide comprehensive spatial information. Three-dimensional cartographic studies meet the accuracy requirements set for traditional 2D stu-dies, and additionally, they naturally connect the place where the phenomenon occurs with its spatial location. Due to the scale of the objects and difficulties in obtaining comprehensive data using only one source, a frequent procedure is to integrate measurement, cartographic, photo-grammetric information and databases in order to generate a comprehensive study in the form of a 3D map. This paper presents the method of acquiring and processing, as well as, integrating data from TLS and UAVs. Clouds of points representing places and objects are the starting point for the implementation of 3D models of buildings and technical objects, as well as for the con-struction of the Digital Terrain Model. However, in order to supplement the spatial information about the object, the geodetic database of the record of the utilities network was integrated with the model. The procedure performed with the use of common georeferencing, based on the global coordinate system, allowed for the generation of a comprehensive basemap in a three-dimensional form.

The Laplace operator is a differential operator which is used to detect edges of objects in digital images. This paper presents the properties of the most commonly used fifth-order pixels Laplace filters including the difference schemes used to derive them (finite difference method – FDM and finite element method – FEM). The results of the research concerning third-order pixels matrices of the convolution Laplace filters used for digital processing of images were presented in our previous paper: The mathematical characteristic of the Laplace contour filters used in digital image processing. The third order filters is presented byWinnicki et al. (2022). As previously, the authors focused on the mathematical properties of the Laplace filters: their transfer functions and modified differential equations (MDE). The relations between the transfer function for the differential Laplace operator and its difference operators are described and presented here in graphical form. The impact of the corner elements of the masks on the results is also discussed. A transfer function, is a function characterizing properties of the difference schemes applied to approximate differential operators. Since they are relations derived in both types of spaces (continuous and discrete), comparing them facilitates the assessment of the applied approximation method.

The article presents the reviewed and summarised research activities of the Polish research groups on gravimetry and gravity field modelling in the period of 2019–2022. It contains the results of absolute gravity surveys for the maintenance of the international gravity reference level in Poland and Europe, and for geodynamic research with an emphasis on metrological aspects. It also contains relative gravimetry issues as well as the results of marine gravity surveys in the southern Baltic Sea. Non-tidal gravity changes were extensively investigated. Long-term gravity variations were monitored at the Borowa Gora Geodetic-Geophysical Observatory and in a few other locations in Poland. The contribution of gravimetric records to seismic studies was investigated. Temporal variations of the gravity field from GRACE (Gravity Recovery and Climate Experiment) and GRACE-FO (GRACE Follow-On) data, in particular, deformations of the Earth’s surface as well as temporal variations of heights, total water storage and groundwater storage were investigated. Moreover, GRACE-based products and the performance of monthly Global Geopotential Models (GGMs) were a subject of research. GGMs developed in last years were evaluated. The research on developing new approaches in geoid modelling and their validation was conducted. New regional and local geoid models were determined for Poland and Ethiopia. The use of different techniques for estimating the absolute sea level at sites of the selected network in the Baltic Sea was investigated.

The Laplace operator is a differential operator which is used to detect edges of objects in digital images. This paper presents the properties of the most commonly used third-order 3x3 pixels Laplace contour filters including the difference schemes used to derive them. The authors focused on the mathematical properties of the Laplace filters. The basic reasons of the differences of the properties were studied and indicated using their transfer functions and modified differential equations. The relations between the transfer function for the differential Laplace operator and its difference operators were described and presented graphically. The impact of the corner elements of the masks on the results was discussed. This is a theoretical work. The basic research conducted here refers to a few practical examples which are illustrations of the derived conclusions.We are aware that unambiguous and even categorical final statements as well as indication of areas of the results application always require numerous experiments and frequent dissemination of the results. Therefore, we present only a concise procedure of determination of the mathematical properties of the Laplace contour filters matrices. In the next paper we shall present the spectral characteristic of the fifth order filters of the Laplace type.

Remote sensing technology and the Earth system data it can obtain can provide great support for the monitoring and management of protected areas. These data can provide the ecological indicators of a place. It is very important to understand the situation concerning the natural land elements of a pro-tected area and to stop unacceptable actions in time. This paper presents an analysis of the natural elements of the land use/land cover (LULC) in the landscapes of protected areas. Freely available Sentinel-2A (S2A) multispectral data were used to classify the LULC and monitor the situation of protected areas. The research object was Trakai Historical National Park, which is an authentic land-scape in Lithuania. First, the Sentinel-2A image was processed and classified using the random forest algorithm by the special Lithuanian remote monitoring data collection, processing, use and storage system of the Environmental Protection Agency Lithuania. Next, the LULC model was statistically analysed using Quantum Geographic Information System (QGIS) software. The authors recommend automating these processes. The results show that in the period from 2021–2022, the farmland areas (cultivated meadows, decay areas, winter cereals, intensive cultivated crops and natural meadows) in Trakai Historical National Park decreased by 9.2%. Meanwhile, the forest, water and wetland areas increased by 9.6%, which makes it possible to conclude that these changes are beneficial for the ecosystems in this area.

Generally, Least Squares (LS) Method treats only random errors of observation vector in adjustment function models. However, both observation vector and elements of coefficient matrix of adjustment function model contain random errors. Therefore, there is no guarantee that the result of adjustment by LS method is the global optimal solution. Total Least Square (TLS) method is a primary estimation method that treats random errors of observation vector and coefficient matrix in adjustment functional models. Since TLS method take into account both random errors of observation vector and coefficient matrix based on errors-in-variables model, it is possible to improve the accuracy compared with the result of LS method. So TLS method has been applied to different fields of science and technology including signal and image processing, computer vision,communication engineering and geodesy. However, weighted total least square (WTLS) method has been not applied in geodetic network adjustment problem compared with other fields widely. So the purpose of this paper is to summarize the algorithm of WTLS briefly and to propose an application method in adjustment of triangulation network. Key problem in application of WTLS to adjustment of geodetic network is to determine the weight matrix (or cofactor matrix) for elements of coefficient matrix in adjustment function model. In this paper proposed a method to determine cofactor matrix for errors of coefficient matrix in triangulation network, and verifies the effectiveness of suggested method through example applied to triangulation network.

Global Navigation Satellite Systems (GNSS) technology has emerged as a powerful tool for unraveling Earth’s dynamic nature, offering continuous and precise monitoring of geodetic positions with global coverage. This study quantifies the noise magnitude and velocity uncertainty estimates using GNSS-derived coordinate time series data from 31 IGS global stations. It assessed the relationship between the noise level and the uncertainties related to the derived velocities and systematically evaluated the influence of different coordinate solution time spans, satellite orbit/clock products, and GNSS constellation on the noise level and velocity uncertainties. The result gives insights into GNSS velocity estimation, noise characteristics, and the influence of ambiguity resolution. The results suggested that resolving ambiguities and using specific GNSS constellation satellite orbits and clocks solutions enhances the precision of velocity estimates and reduces noise magnitude. The noise levels are observed to be consistently above –0.7 in 5-year solution sets and below –0.8 in 8-year solution sets. There is an average of 30 and 42% reduction in velocity uncertainties due to 3 year increment in solution span using JPL and ESA orbits, respectively. GPS-only solution set appeared to be favorable for high-precision GNSS-based geodynamic applications with increased favourability when the ambiguities are resolved. The identified noise model, GGM+WN, demonstrated the most appropriate noise model in most cases which is not out of place to have been used in quantifying the noise magnitude and velocity uncertainties in this study.

The destruction of the Nova Kakhovka dam in Ukraine on June 6th, 2023, produced an enormous flooding in the entire Kherson region. Thousands of people and agricultural fields were affected, bringing down an economy already devastated by the ongoing war. In addition to that, in the months prior to the collapse, the water level in the reservoir has been firstly decreased to a minimum, before rising it to an all-time maximum. Both these two situations are studied by means of Sentinel-1 SAR images, using the so-called change detection technique, with the aim of identifying those areas that got covered by water due to the Lake Kakhovka level rise and due to the flooding in the downstream region of the dam. The obtained results are then validated through comparison with optical images from Sentinel-2 and Landsat 9 satellites. The initial validation involves a visual assessment of both data types, followed by a more in-depth analysis that includes pixel classification of the optical images. This final step enables a precise quantification and comparison of the extent of the damage. It is clear that the increase of the water level before the dam collapse has worsened the extension and effect of the subsequent flooding.

Water levels in freshwater resources have been descending daily as global temperatures have risen and a coastal recession has occurred. The losses in these water basins have a significant influence on natural life. While drought is a global environmental issue, its consequences may be seen in Turkey. This study looks at the loss of water areas in Burdur Lake, one of Turkey’s major lakes, between 2010 and 2021. The areas were identified using supervised classification, and the classification process was carried out for 2010, 2013, 2016, 2019, and 2021, respectively. Furthermore, several drought detection metrics, such as land surface temperature, soil moisture values, Normalized Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), Palmer Drought Severity Index (PDSI), and precipitation amounts, have been evaluated for the study area between 2010 and 2021. The values of all drought detection indicators were also evaluated monthly for each year of the study. The analysis reveals abnormalities in all parameters, particularly in recent years, when compared to earlier years. Water areas decreased by 36.48% as a result of the classifications, whereas sandy areas increased by 89.85%. Again, the average values of various parameters used for drought detection over the years were compared. As a result, the indicator parameters gave reliable results as well as a means of monitoring the drought.

Land use dynamics describes the changes occurring in an area which can be approximated from a land use and land cover map (LULC). This research aims to assess how the mangrove forest in the Niger Delta Region has degraded. Landsat imagery of 1987, 2002, and 2022 were used to create LULC maps from which change detection of the area derived from supervised classification technique, were investigated. The classification accuracy was determined and the result shows that for 1987, 2002, and 2022 the accuracy score are 82.16%, 82.16%, and 83.97%, respectively and the corresponding kappa coefficients for the epochs are 75.63%, 75.63%, and 78.43%. The producer and user accuracy are high for all the classes except grassland and urban areas. The change detection result showed a net loss in mangrove, grassland, and water bodies between 1987 and 2002 with significant gains for urban and woodlands however significant losses were revealed in the mangrove, woodlands, water bodies, and grassland with gains in only the urban settlement between the 2002 and 2022 study period. The result also revealed that the mangrove forest cover has seen a consistent loss in the two study periods. The Niger Delta Region is a key component of the global climate system and our research provides an accurate assessment of the land use dynamics and the mangrove degradation in the region.

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.

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.

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.

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.

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.