Implementation of the variation of the luni-solar acceleration into GLONASS orbit calculus

In the differential equation system describes the motion of GLONASS satellites (rus. Globalnaya Navigazionnaya Sputnikovaya Sistema, or Global Navigation Satellite System ), the acceleration caused by the luni-solar traction is often taken as a constant during the period of the integration. In this work-study, we assume that the acceleration due to the luni-solar traction is not constant but varies linearly during the period of integration following this assumption; the linear functions in the three axes of the luni-solar acceleration are computed for an interval of 30 min and then implemented into the differential equations. The use of the numerical integration of Runge-Kutta fourth-order is recommended in the GLONASS-ICD (Interface Control Document) to solve for the differential equation system in order to get an orbit solution. The computation of the position and velocity of a GLONASS satellite in this study is performed by using the Runge-Kutta fourth-order method in forward and backward integration, with initial conditions provided in the broadcast ephemerides file.

Transformations between the Slovenian and international terrestrial reference frames

The current Slovenian terrestrial reference frame (D96-17) is a static frame based on GNSS technology. An additional transformation connecting it with the new realisation of ETRS89 accepted by EUREF (D17) gives the D96-17 a specific character. In order to ensure a high-quality national terrestrial reference frame, connection to the current realisation of ITRS is needed. This change is particularly important in the light of the intended transition to the semi-kinematic terrestrial reference frame, supported by a national geo-kinematic model. Transformations between the current national and international terrestrial reference frames are discussed in detail in the present paper. Processes, equations, and parameters of datum transformations are given in both directions (forward and inverse), step-by-step and direct ones, rigorous and simplified (approximate). Furthermore, an analysis of coordinate differences between current Slovenian and international terrestrial reference frames and an analysis of coordinate errors for various simplifications of transformation between both reference frames are given. This allows users to choose an optimal transformation solution to meet their requirements. The role and importance of transformations under consideration in the positioning procedures and the precise navigation are also addressed.

The willingness of volunteers to report changes on topographic maps

Various possibilities for collecting volunteer-provided geographical information in geodesy make it possible to engage volunteers for different purposes. In this paper, a study of the willingness of volunteers to report changes on topographic maps based on an online survey is presented. The survey was answered by 653 Slovenian respondents who use various online or classic topographic maps in their free time or at work and are willing to report their knowledge of changes in space or errors in maps to the map-updating institution. The survey's main finding is that 56% of respondents would use any online application to report changes on maps, 38% of respondents would prefer to report changes via email, and only 4% of respondents would prefer to report changes by phone. We also analysed the potential use of different functionalities of a web application for collecting changes and found that the most important functionalities for volunteers are those that give the most in-depth feedback (i.e., that a contribution has been submitted, that it is being verified, that it has been considered, that it has been deleted). The willingness of potential volunteers to use the various proposed functionalities also frequently depends on their current involvement with social networking sites or in volunteer associations and on their age group.

Competitiveness and cohesion in Romania's regional development: a territorial approach

The assessment of the socio-economic disparities at the regional level is one of the priority development topics. In particular, in formerly socialistic-planned countries, the development driven by the transition period, the accession to the European Union and the economic crisis, the regional disparities are present. The main aim of the research has been to identify the most competitive and the most cohesive Development Regions in Romania by computing, mapping and analysing two secondary indices (Territorial Competitiveness and Territorial Cohesion). Overall, the investigation shows that economic performance is more consolidated in central and western regions based on their mature and innovative industries, better-developed services and urbanisation/suburbanisation processes, while the eastern and southern development regions, with predominantly rural traits, experienced a significant industrial decline and social deprivation. The most competitive Development Region is Bucharest-Ilfov, given the advantage conferred by Bucharest Capital City, the main economic and social polarising centre in Romania. For reducing regional disparities, the Cohesion Policy should allocate increased funds for countries with least developed regions. The study provides the result of quantitative and qualitative analysis on the regional-level territorial disparities in Romania that could easily be considered as guidelines in the decision-making process while trying to achieve the competitiveness and cohesion goals.

Integration of land cadastre with spatial plan data

Establishing a multi-purpose cadastre, especially in terms of upgrading cadastral contents with the various spatial data, such as land use, is a challenge in Slovenia and internationally. Land use strongly affects spatial planning, development, and management, so high-quality spatial integration of the land cadastre with spatial plans data is crucial for effective land management. In the first part of the article, we reviewed the literature and documents that prescribe guidelines for the development of the land cadastre; we use these guidelines as a basis for developing a proposed method of linking and harmonising the data of the land cadastre with the spatial plan data. Land use is specified in spatial plans, and we linked it to the graphical and attribute land cadastre data layer. We tested the method in selected study areas in Prekmurje with a high-quality cadastre in the municipalities of Kramarovci and Nemčavci. As a result, we presented land use data directly in the land cadastre database, which requires simultaneous land use and cadastre maintenance. Based on the results for selected cadastral municipalities, we critically evaluated the proposed method.

Protective restrictions on the acquisition of agricultural land: the impact on the land market on the example of Lithuania

During the period of about 15 years, there were several attempts to regulate land tenure in Lithuania by changing the procedure of land acquisition and imposing some restrictive measures for the acquisition of agricultural land. This research aimed to determine the impact of those restrictive measures on the land market. This article represents the analytical results of the statistical data on agricultural land privatisation and market sales in respect of changes in legal acts. According to the analysis, changes in land acquisition procedure had no negative effect on land privatisation and volumes of land sales nor on land sale prices during the transitional period of limited access for foreign buyers in 2004–2014. The volatility of land sales during the transitional period can be explained by the natural market cyclicality, while the steady growth of prices indicates that the land market has not yet reached its long-run equilibrium. The new regulative provisions adopted in 2014 after the transitional period was over were intended to prevent land concentration and had a positive, yet momentary, effect on the supply of private agricultural land. A significant increase in land prices after introducing those provisions was caused by the ceased supply of state land and some other causes that were not analysed in this paper.

True orthophoto in urban areas

True orthophoto is a better product than a classical orthophoto in urban areas, because buildings are depicted in the correct plane position, and the content around the building is also visible. The main goal of our research was to verify two approaches of a true orthophoto production: a) true orthophoto production based on digital terrain model and digital building model, and b) automatic true orthophoto production. We performed the research in two test areas within the Municipality of Ljubljana. We compared the both procedures and the produced true orthophotos with the classical orthophoto, and assessed the production time component as well. To produce true orthophoto, larger overlapping of aerial images is required, thus the time for aerial surveying is increased by approximately 25 percentage. The time of manual work, compared to classical orthophoto production, is lower by the factor 0.27 for automatically produced true orthophoto, and is greater by the factor 2.75 for the true orthophoto based on digital terrain model and digital building model. Aesthetic appearance of automatically produced orthophoto has only minor shortcomings on the buildings’ roof edges which are slightly serrated. Considering all the mentioned aspects, the automatically produced true orthophoto is competitive with the classical orthophoto.

Proposal of real estate mass valuation in Slovenia based on generalised additive modelling approach

The present paper discusses the heterogeneity of the apartment market. For this purpose, we have developed the model for the mass valuation of apartments in the Republic of Slovenia. The construction of the mass valuation model is based on the generalised additive model approach. In this paper, the development of the model is presented. In the experimental part, the analysis of the results of the two models is performed. The dependent variable (the price of an apartment) is distributed according to the Gaussian and the gamma distributions. Particular attention has been paid to the impact of the transaction time on the apartments’ transaction value. The results of the model are also compared with the results of the mass valuation model in the Republic of Slovenia, which is carried out cyclically and iteratively, the results of which depend on the results (and mass valuation models) of previous cycles.

What have we learnt from ICESat on greenland ice sheet change and what to expect from current ICESat-2

Ice-sheet mass balance and ice behaviour have been effectively monitored remotely by space-borne laser ranging technology, i.e. satellite laser altimetry, and/or satellite gravimetry. ICESat mission launched in 2003 has pioneered laser altimetry providing a large amount of elevation data related to ice sheet change with high spatial and temporal resolution. ICESat-2, the successor to the ICESat mission, was launched in 2018, continuing the legacy of its predecessor. This paper presents an overview of the satellite laser altimetry and a review of Greenland ice sheet change estimated from ICESat data and compared against estimates derived from satellite gravimetry, i.e. changes of the Earth’s gravity field obtained from the GRACE data. In addition to that, it provides an insight into the characteristics and possibilities of ice sheet monitoring with renewed mission ICESat-2, which was compared against ICESat for the examination of ice height changes on the Jakobshavn glacier. ICESat comparison (2004–2008) shows that an average elevation change in different areas on Greenland varies up to ±0.60 m yr−1. Island’s coastal southern regions are most affected by ice loss, while inland areas record near-balance state. In the same period, gravity anomaly measurements showed negative annual mass balance trends in coastal regions ranging from a few cm up to -0.36 m yr-1 w.e. (water equivalent), while inland records show slightly positive trends. According to GRACE observations, in the following years (2009–2017), negative annual mass balance trends on the coast continued.

Testiranje in izboljšava horizontalne datumske transformacije: študija primera v Bosni in Hercegovini

This study evaluates the applicability of different models of coordinate transformation between local and global geodetic datums. The results indicate the grid-based method as the best solution, assuming a sufficient density of tie points. Transformation based on a limited number of tie points, which do not reflect the real state of the survey basis in a particular area, have limited possibilities to reduce nonuniform and unequally distributed distortions that are usually found in the spatial data. This inevitably leads to the degradation of accuracy of transformation results, which is unacceptable. By using the optimal resolution grid model, which includes geodetic points from the area of the cadastral municipality that is being transformed, much better results are achieved compared to the model of distortion shifts used in the Federation of Bosnia and Herzegovina.