In the paper a frequency method of filtering airborne laser data is presented. A number of algorithms developed to remove objects above a terrain (buildings, vegetation etc.) in order to obtain the terrain surface were presented in literature. Those all methods published are based on geometrical criteria, i.e. on a specific threshold of elevation differences between two neighbouring points or groups of points. In other words, topographical surface is described in a spatial domain. The proposed algorithm operates on topographical surface described in a frequency domain. Two major tools, i.e. Fast Fourier Transform (FFT) and digital filters are used. The principal assumption is based on the idea that low frequencies are responsible for a terrain surface, while high frequencies are connected to objects above the terrain. The general guidelines of this method were for the first time presented at (Marmol and Jachimski, 2004). Due to the fact that the preliminary results showed some limitations, two-stage filtering algorithm has been introduced. The frequency filter was modified in such a manner that different filter parameters are used to detect buildings than those to recognize vegetation. In the first stage of data processing the filtering concerning elimination of points connected with urban areas was applied. The low-pass filter with parameters determined for urban area was used for the whole tested terrain in that stage. The purpose of the second stage was to eliminate vegetation by using the filter for forest areas. The presented method was tested by using data sets obtained in the ISPRS test on extracting DTM from point clouds. The results of using the two-stage algorithm were com- pared with both reference data and with filtering results of eight method reported to ISPRS test. A numerical comparison of the filter output with a reference data set shows that the filter generates DTM of a satisfactory quality. The accuracy of DTM produced by the frequency algorithm fits the average accuracy of eight methods reported in the ISPRS test.

A number of new satellite-only Global Gravity Models (GGMs) become progressively available based on the CHAMP and GRACE satellite mission data. These models promise higher (compared to older GGMs) accuracy in the determination of the low and medium harmonics of the Earth's gravity field. In the present study, the latest GGMs generated from CHAMP and GRACE data (namely EIGEN2, EIGEN3p, GGM0IC, GGM0IS and GRACED IS) have been studied with respect ro their accuracy and performance when used in gravity field approximation. A spectral analysis of the new models has been carried out, employing their degree and error-degree variances. In this way, their performance against each other and with respect to EGM96 was assessed, and the parts of the gravity field spectrum that each model describes more accurately have been identified. The results of the analysis led to the development of a combined geopotential model, complete to degree and order 360, whose coefficients were those of CHAMP until degree 5, then GRACE until degree 116, and EGM96 for the rest of the spectrum. Finally, a validation of all models (the combined included) has been performed by comparing their estimates against GPS/levelling data in land areas and TOPEX/Poseidon sea surface heights in marine regions. All rests have taken place over Greece and the eastern part of the Mediterranean Sea. From the results obtained it was concluded that the combined GGM developed provides more accurate results (compared to EGM96), in terms of the differences with the control datasets, at the level of 1-2 cm geoid and 1-2 mGal for gravity (ICT). Furthermore, the absolute geoid accuracy that the combined GGM offers is 12.9 cm (ICT) for 11 = 120, 25 cm for 11 = 200 and 33 cm for n = 360, compared to 29 cm, 36 cm and 42 cm for EGM96, respectively.

The paper discusses the problems of the calibration process of very close range semi-metric digital cameras. Using such cameras for precise measurement of small objects, the photographs have to be taken at a very large scale, ranging from 1 :20 to 1:50. To ensure the submillimetre accuracy of the photogrammetric measurement, the specific calibration tests and procedures for determination of the interior orientation parameters, including the coefficients for image systematic errors, must be applied. The results of two calibration approaches, based on 3D and 2D calibration tests, have been presented in the paper. The experiment is a part of the research project concerning the numerical modelling of small 3D fragments of the broken archaeological items for reconstruction of the context of the archaeological monument.

The objective of this research paper is to identify the surveying and legal problems occurring as part of the practical implementation of transforming the right of perpetual usufruct into ownership title in the context of the new regulations that have been in force since 1 January 2019. This is a consequence of the Act of 20 July 2018 on the transformation of the right of perpetual usufruct of the land developed for residential purposes into the ownership title to this land. The research problem of this study is the analysis of the real estate subjected to the transformation of the right of perpetual usufruct into the ownership title in the context of the new regulations in force since 1 January 2019. The conducted research has resulted in the identification of the problems related to the interpretation of these new regulations, also in defining the scope of real properties subjected to the transformation, issuing certificates confirming the transformation, and entering the effects of this transformation into land and mortgage registers. These problems may hinder the practical implementation of the transformation process as well as hamper the execution of real estate transactions. In order to illustrate the implementation scale of these new regulations, the author of this research paper has defined the purposes for which the real properties in the selected city were let into perpetual usufruct, the approximate scope of the properties subject to the transformation and the financial consequences of this process.

In GIS systems, the neighbourhood of areas within an analysed region is a term applied usually to raster-screened data. The aim of the study was to adapt this term to vector and descriptive data as well as to systemize models of so defined neighbourhood. The starting point was the assumption that the basic area neighbourhood model may be based on spatial data illustrated with a graph and described with a neighbourhood matrix. It provides the basis for building subsequent models, that are linked with the introduction of new neighbourhood measures, i.e. measures resulting from the characteristics of areas entered in tables of their attributes. Based on the proposed models, spatial analysis related to area neighbourhood can be performed and aggregate models, considered essential in multidimensional analysis of neighbourhood can be developed.

The paper presents an attempt to assess how random errors and systematic errors in gravity data affect the quality of the geoid model when it is computed using the FFf technique. Three groups of numerical tests were conducted with the use of gravity anomalies for Poland on 2' x 2' and 5' x 5' grid and with simulating random and systematic errors. In the first test, the effect of random errors on calculated geoid undulations was investigated, in the second one - the effect of systematic errors, and in the last one - the combined effect of both random and systematic errors. The effect of density of data set on the propagated error in geoid height was also examined. The results of numerical tests made possible to evaluate the effect of random errors as well as systematic errors on the accuracy of computed geoid undulation. They were also useful in evaluating the quality of the gravimetric quasigeoid model for Poland.

Movement is one of the most spectacular phenomena involving glaciers. Deter- mining glacier surface velocity is now a routine aspect of glaciological studies. These are geodetic methods, especially satellite positioning, that most frequently is applied in such work. Using the Hans Glacier (SW Spitsbergen) as an example, the presented paper is an attempt at defining the time resolution limit of changes in the velocity determined using GPS positioning technology. A test network was established in the area of the examined glacier in order to define the size and variability of the main satellite positioning biases as well as to define their impact on determining position and the calculated velocity. A discussion relating to achieved accuracy (differentiated from measurement precision) for baselines of a length of several kilometres in the high latitudes has also been presented.

Many different characteristics affect the land prices. This work attempts to analyse the characteristics of agricultural parcels, which significantly affect the variability of agricultural land prices. The article presents the methodology of selection land parcel characteristics, rules for the selection of factors and possibility of automatic acquisition of data in mass valuation process. The research aims at selecting determinants of agricultural land parcels price and evaluate theirs significance in a local market for the purpose of land values map elaboration. Using advanced statistical analysis of a non-linear influence of a parcel inherent characteristics on its price we proved that in the relatively small area, like commune, only a few characteristics are essential, They are: parcel size, shape and location expressed by distance to the commune centre, paved roads and homestead buildings. Therefore, these ones should be used for elaboration of land values map. Soil quality and a cropland type although significant for the land prices do not diversify land prices in local market. The novelty of the research relays on determination of non-linear influence of parcel characteristics on variation of agricultural land values based on the correlation ratio (h eta). The research was conducted for the undeveloped agricultural lands located in south-west Poland, the rural municipality Krotoszyce.

In this article the author follows progressive evolution in web design that has been observed in Google Maps over the last 13 years (2005–2018). The analysis includes the graphic presentation of buttons, their layout and the changes in the functionality of the website. The results of the analysis corroborate the argument that it is possible to adapt the existing concept of progressive evolution, to the needs of Internet cartography. In the process of the analysis several crucial changes were spotted, such as the fact that as a result of the technological advancement the need to scroll the map with up, down, left and down buttons disappeared, being supplanted by the dragging function. In article all the discussed changes in Google Maps as an application for desktop computers and laptops, as well as a mobile application, prove that the product has been constantly improved. In the author’s opinion, the crucial aspect is to enrich the web map in the non-invasive way to make it as user-friendly and easy to use as possible. The synthetic juxtaposition allowed one to highlight the evolution, considered by the author an important feature of the non-invasive way of introducing changes. The author notes that progressive evolution on Google Maps and other internet maps will continue. It is important that the user’s needs are noticed during these changes.

The radar method, executed with the use of ground penetrating radars - the georadars, belongs to non-intrusive methods of positioning subsurface structures and objects. The direct result of the survey is the so-called radargram - a radar image, that is a vertical cross-section of the penetrated medium. It brings an information on the existence and mutual position of ground layers and subsurface structures and objects. The radargram, as the direct result of measurement, demands further processing for its interpretation and use. The consecutive steps leading from a non-metric radargram to the metric 3D model, based on corresponding surveying and georadar data are presented. The paper concentrates on the problem of broadening the scope of interpretation and applications of georadar surveys thanks to proper integration of advanced filtering programs, graphical software and programs from the CAD and SIT environment. The aim of the integration is a metric 3D model of subsurface objects and structures located with the georadar method. The ways and stages of generation of the spatial subsurface models, presented in the paper, complement surveying sources of data for thematic maps.

In monitoring vertical displacements in elongated structures (e.g. bridges, dams) by means of precise geometric levelling a reference base usually consists of two subgroups located on both ends of a monitored structure. The bigger the separation of the subgroups, the greater is the magnitude of undetectable displacement of one subgroup with respect to the other. With a focus on a method of observation differences the question arises which of the two basic types of computation datum, i.e. the elastic and the fixed, both applicable in this method, is more suitable in such a specific base configuration. To support the analysis of this problem, general relationships between displacements computed in elastic datum and in fixed datum are provided. They are followed by auxiliary relationships derived on the basis of transformation formulae for different computational bases in elastic datum. Furthermore, indices of base separation are proposed which can be helpful in the design of monitoring networks. A test network with simulated mutual displacements of the base subgroups, is used to investigate behaviour of the network with the fixed and the elastic datum being applied. Also, practical guidelines are given concerning data processing procedures for such specific monitoring networks. For big separation of base subgroups a non-routine procedure is recommended, aimed at facilitating specialist interpretation of monitoring results.

The paper presents a method of construction of cylindrical and azimuthal equalarea map projections of a triaxial ellipsoid. Equations of a triaxial ellipsoid are a function of reduced coordinates and functions of projections are expressed with use of the normal elliptic integral of the second kind and Jacobian elliptic functions. This solution allows us to use standard methods of solving such integrals and functions. The article also presents functions for the calculation of distortion. The maps illustrate the basic properties of developed map projections. Distortion of areas and lengths are presented on isograms and by Tissot’s indicatrixes with garticules of reduced coordinates. In this paper the author continues his considerations of the application of reduced coordinates to the construction of map projections for equidistant map projections. The developed method can be used in planetary cartography for mapping irregular objects, for which tri-axial ellipsoids have been accepted as reference surfaces. It can also be used to calculate the surface areas of regions located on these objects. The calculations were carried out for a tri-axial ellipsoid with semi-axes a = 267:5 m, b = 147 m, c = 104:5 m accepted as a reference ellipsoid for the Itokawa asteroid.

Activities of the Polish research gSDroups concerning gravity field modelling and gravimetry in a period of 2015–2018 are reviewed and summarised in this paper. The summary contains the results of research on the evaluation of GOCE-based global geopotential models (GGMs) in Poland and geoid modelling. Extensive research activities are observed in the field of absolute gravity surveys, in particular for the maintenance of national gravity control in Poland, Sweden, Denmark, the Republic of Ireland and in Northern Ireland as well as for geodynamics with special emphasis on metrological aspects in absolute gravimetry. Long term gravity variations were monitored in two gravimetric laboratories: the Borowa Gora Geodetic-Geophysical Observatory, and Jozefoslaw Astrogeodetic Observatory with the use of quasi-regular absolute gravity measurements as well as tidal gravimeter records. Gravity series obtained were analysed considering both local and global hydrology effects. Temporal variations of the gravity field were investigated using data from GRACE satellite mission as well as SLR data. Estimated variations of physical heights indicate the need for kinematic realization of reference surface for heights. Also seasonal variability of the atmospheric and water budgets in Poland was a subject of investigation in terms of total water storage using the GLDAS data. The use of repeatable absolute gravity data for calibration/validation of temporal mass variations derived from satellite gravity missions was discussed. Contribution of gravimetric records to seismic studies was investigated. The bibliography of the related works is given in references.

Modelling quasigeoid with centimetre accuracy requires taking into account irregularities of topography in the vicinity of a gravity station. i.e. the terrain correction w surveyed gravity. Accuracy of determination of the terrain correction affects quality of quasi geoid model determined. It depends on the resolution and accuracy of terrain data that usually is provided in the form of a digital terrain model DTM. Investigations were conducted with the use of the Digital Terrain Elevation Data - DTED2 model developed for Poland according to the NATO-STANAG 3809 standard, as well as global models SRTM3 and SRTM30 (The Shuttle Radar Topography Mission). Also height data from the gravity database was considered. The prism method of determination of terrain corrections was applied in majority of numerical tests. Practical method for determining the optimum radius of the integration cap considering roughness of topography as well as required accuracy of terrain corrections was developed. The effect of vertical and horizontal uncertainty of a DTM as well as its resolution on the quality of the terrain corrections was investigated. The terrain corrections obtained using a prism method were also compared with the respective ones calculated using the FIT approach. The usefulness of the available topography data for precise terrain correction computation in Poland was discussed. The results of the investigations were used to determining the strategy of computation of the terrain corrections to point gravity data in the gravity database for Poland. The "2005" terrain correction set calculated for I 078 046 gravity stations contributes to the increase of precision of gravimetric quasigeoid models developed for Poland.

The aim of the paper is the comparison of the least squares prediction presented by Heiskanen and Moritz (1967) in the classical handbook “Physical Geodesy” with the geostatistical method of simple kriging as well as in case of Gaussian random fields their equivalence to conditional expectation. The paper contains also short notes on the extension of simple kriging to ordinary kriging by dropping the assumption of known mean value of a random field as well as some necessary information on random fields, covariance function and semivariogram function. The semivariogram is emphasized in the paper, for two reasons. Firstly, the semivariogram describes broader class of phenomena, and for the second order stationary processes it is equivalent to the covariance function. Secondly, the analysis of different kinds of phenomena in terms of covariance is more common. Thus, it is worth introducing another function describing spatial continuity and variability. For the ease of presentation all the considerations were limited to the Euclidean space (thus, for limited areas) although with some extra effort they can be extended to manifolds like sphere, ellipsoid, etc.

In this publication, the strategy of land resources administration is presented on the basis of consideration of proposed result factors. The research methodology is based on the use of the PESTLE analytical model in conjunction with economic-mathematical modeling. The scientific novelty of the publication is developing the technology of administration of land resources on the basis of cadastral and other statistical information, which allows obtaining scientifically grounded solutions on the use of land resources. Considering the process of Land Resources Administration as a procedure based on making certain decisions when creating a management system which takes into account the internal and external relationships in this system, the postulate is about determining the degree of trust in this system, establishing economic, environmental and social risks when using it. To a certain extent, the process of Land Resources Administration is a prediction of the effective use of this natural potential in the future. It should be noted that the reliability of the forecast decision depends on the nature and parameters of uncertainties and the duration of their validity. Consequently, while making operational decisions on land resources for a short perspective, the forecasting is more reliable than for a long one. It becomes an effective mechanism of objective evaluation of the state of land resources and the prospects for their use. In this publication the main influencing decision making factors and the technological scheme of the solution of the problem are given.

Improving the technology for determining the investment attractiveness of urban land requires the development and implementation of an integrated assessment method. In this context, the formation of a system of indicators used for the integral assessment is very important. Based on the two-level system of factors proposed in the article, which influence the formation of investment attractiveness of urban land and using a hierarchical classification method, an appropriate system of indicators is constructed. The transition from factors to indicators is ensured by the established causal dependence, which characterizes the causal relationships between factors and functional-planning, territorial indicators, indicators of engineering and territory improvement, indicators of ecology, historical and cultural significance. In article it is proposed to consider the information support as a set of functional-planning, territorial, engineering support and improvement of the territory, environment, ecology, historical and cultural indicators, which are formed on the basis of normative legal acts, systematization of theoretical and methodological provisions, considering technological features and factors, which affect the investment attractiveness of land. Considering the existing directions for the implementation of technology for assessing the investment attractiveness of urban land, the economic, spatial, complex, multifactorial, rating approaches and approach based on the tools and results of mathematical modelling, considering technical, environmental, social and economic factors, which influence the investment attractiveness of urban land have been proposed.

The paper addresses the problem of solving overdetermined systems of linear equations by means of methods of robust estimations, which eliminate the effect of outliers on the estimation results. The process of estimating a vector of parameters was accomplished by means of circular in structure neural networks. Formulating the problem in the aspect of a method for estimating parameters requires formulating an energy function (objective function) whose form was modified by means of a determined weighting function. In the final part of the paper the effectiveness of the methods described was evaluated in terms of controlling and diagnosing a geodetic observation system. The article is merely an introduction to a broadly understood problem of geodetic uses of robust estimators.

The paper presents the least admissible dimensions of black lines of spatial object images, according to Saliszczew, adjusted to the needs of database generalization. It is pointed out, that the adjusted dimensions are in agreement with the cartographic norm included in the National Map Accuracy Standards , and their application to the generalization 1 will allow, for any map scale, the determination of the: • value of the scale-dependent parameter of the generalization process, without user action; • measure of recognizability of the shortest black line section on the map, what helps to obtain unique results of line generalization; • measure of recognizability of black lines in the image – using a standard (elementary triangle) – helpful in obtaining unique result of line simplification, and an assessment of the process; • recognizability distance between lines of close buildings, securing unique aggregation of them; • verification of spatial object image lines visualization. The new solutions were tested with the Douglas-Peucker (1973) generalization algorithm, modified by the author, which treats the minimal dimensions as geometric attributes, while object classes and their data hierarchy as descriptive attributes. This approach secures uniqueness of results on any level of generalization process, in which data of spatial objects in the DLM model are transformed to conform with the requirements for the DCM model data.

The purpose of the study was an assessment of LiDAR point clouds for automating the mapping of land use and land cover changes, mainly land abandonment and the process of secondary forest succession. Detailed information about land cover was determined based on airborne laser scanning data. The presented study focuses on the analysis of the spatial range and structure of vegetation. The study area was located in Milicz district in the voivodeship of Lower Silesia – the central west part of Poland. The areas of interest were parcels where agricultural land had been abandoned and forest succession processes had progressed. Analysis of the spatial range of the secondary forest succession was carried out using a reclassified nDSM. Reclassification of the nDSM was done using > 1 m, > 2 m and > 3 m for the pixel values, representing the height of vegetation above the ground. Parameters such as height of vegetation, standard deviation of height and cover density were calculated, to show the process of the increase in forest succession on abandoned agricultural land. The results confirmed a discrepancy between the cadastral data and the actual use of the plots. In the study area, more than three times as much forested and wooded area was detected than had been recorded in official databases. Analyses based on airborne laser scanning point clouds indicated significant diversity in the vertical and horizontal structure of vegetation. The results demonstrated gradual succession of greenery in the research area.

The paper presents a general concept of geodetic observations adjustment based on application of the Edgeworth' series and the principle of an alternative choice. The Edgeworth' series approximates the empirical distribution of measurement errors and gives an opportunity to modify the empirical characteristics of errors distribution. The method of estimation used is based on the principle of the alternative choice. Its natural robustness for outliers was the basis for newly created method called PAC-E. The paper presents the algorithm and some numerical tests that were carried out to compare the results of the proposed method with the results of the classical LS adjustment. Special attention was paid on the effect of non-zero excess and robustness of the proposed method.

Urbanization has a far-reaching impact on the environment, economy, political and social processes. Therefore, understanding the spatial distribution and evolution of human settlements is a key element in planning strategies that ensure the sustainable development of urban and rural settlements. Accordingly, it is very important to map human settlements and to monitor the development of cities and villages. Therefore, the problem of settlements has found its reflection in the creation of global databases of urban areas. Global settlement data have extraordinary value. These data allow us to carry out the quantitative and qualitative analyses as well as to compare the settlement network at a regional, national and global scale. However, the possibility of conducting both spatial and attribute analyses of these data would be even more valuable. The article describes how to prepare raster data so that they can be implemented into a vector database. It answers the questions whether it is possible to combine these data with databases available in Poland and what benefits it brings. It presents the methods of data generalization and the optimization of time and disk space. As a result of the study, two vector databases with GUF data were developed. The first database resolution is similar to the original (~12 m resolution) database, the second database contains less detailed (~20 m resolution) data, generalized using mathematical morphology. Both databases have been enriched with descriptive data obtained from the National Geodetic and Cartographic Resource.

Statistical moments have been used in different applications as in shape analysis of object, pattern recognition, edge detection texture analysis etc. The idea is to use the moments as features of high level for surface matching. The essential goal of surface matching is to determine transformation parameters between two surfaces generated in TIN or DEM without identical points. Statistical moments are considered as features that are applied to solve that goal, One of the main problems with using statistical moments for surface matching and for other applications is a very expensive computation time. To overcome this difficulty many algorithms have already been proposed. New approach of efficient computation of inertial moments for surface matching is proposed in the paper. The approach is based on Green's theorem that allows for transforming double integral into a line integral. In the consequence computation time of inertial moments of a single TIN-model (triangle) is reduced by a factor 4 as compared with time consumed by the use of direct method of double integral. The direct computation using line integral, that does not involve any approximation, ensures preservation of the accuracy of computed moments.

In recent years, the rate of urban growth has increased rapidly especially in Egypt, due to the increase in population growth. The Egyptian government has set up new cities and established large factories, roads and bridges in new places to solve this trouble. This paper investigates the change monitoring of land surface temperature, urban and agricultural area in Egypt especially Kafr EL-Sheikh city as case study using high resolution satellite images. Nowadays, satellite images are playing an important role in detecting the change of urban growth. In this paper, cadastral map for Kafr El-Sheikh city with scale 1:5000, images from Landsat 7 with accuracy 30 meters; images from Google Earth with accuracy 0.5 meter; and images from SAS Planet with accuracy 0.5 m are used where all images are available during the study period (for year’s 2003, 2006, 2009, 2012, 2015 and 2017). The analysis has been performed in a platform of Geographical Information System (GIS) configured with Remote Sensing system using ArcGIS 10.3 and ERDAS Imagine image processing software. From the processing and analysis of the specified images during the studied time period, it is found that the building area was increased by 28.8% from year 2003 up to 2017 from Google Earth images and increased by percentage 34.4% from year 2003 up to year 2017 from supervised Landsat 7 images but for unsupervised Landsat 7 images, the building area was increased by percentage 35.9%. In this study, land surface temperature (LST) was measured also from satellite images for different years through 2003 until 2017. It is deduced that the increase in the building area (urban growth) in the specified city led to increase the land surface temperature (LST) which will affect some agricultural crops. Depending on the results of images analysis, Forecasting models using different algorithms for the urban and agricultural area was built. Finally, it is deduced that integration of spacebased remote sensing technology with GIS tools provide better platform to perform such activities.