At the moment all three Baltic countries – Estonia, Latvia and Lithuania – use Baltic Normal Height System 1977 as a national height system. But the European Union regulations declared the European Vertical Reference System as a national height system. For height transformation there is a transformation formula for each European country. After calculations it is seen that height difference between Baltic Normal Height System 1977 and the European Vertical Reference System depends on point location in the territory (coordinates). This unequal height difference between both height systems will cause unequal height values on border connection points between the Baltic countries.

Along with the development of the technological possibilities, the Global Positioning Satellite System (GNSS) is increasingly used in geodetic measurements. Using GNSS, measurements are performed in horizontal plane as well as for point elevation determination. The aim of the article is to demonstrate that the GNSS measurements’ static mode has a high accuracy. To achieve the aim the following objectives were set: 1) to perform global positioning measurements in Class I national leveling network, 2) to calculate the elevation above the sea level, 3) to evaluate the accuracy of performed GNSS measurements. The following research methods were used: static measurement method and analytical method for comparison of the obtained data.

The article presents the research study of the current state and condition of the geodetic base (polygonometric) network for Kaunas city and region as well as the aspects of its compiling. The geodetic base compiled in the post-war years is considered to be of high quality and is used nowadays. The still existing polygonometric network is seldom studied and thus it remains little known. For the purpose of defining the current state of the geodetic base networks, the search for the points in Karmėlava neighbourhood of Kaunas region has been provided. From the total number of 22 points to be searched, five (i.e. 22 percentage) were determined, but only four points (i.e.18 percentage) were appropriate for measurements. The majority of the points has been destroyed during the construction of the residential buildings or roads, or after the reconstruction works. The measurements have been taken by Trimble R6, by RTK method, 10 times for each point. The most reliable value of the measured geodetic points X and Y were defined as well as the errors of the mean square for one measurement and of the average. The results of the survey (100 respondents) showed that the majority of the professionals apply the points of the polygonometric network when making measurements. However, the problems related to a rather rear usage of the network and the aggravated search of the polygonometric points were encountered. A significant part of the professionals suggested the restoration of the polygonometric network.

The role of space geodetic techniques combination is becoming increasingly important to calculate the geodetic parameters. It has an intention of using the advantages and complementarity of different techniques to achieve the best solution. Estimation of geodetic parameters from observations mainly was done by least squares adjustment within the Gauss - Markov model. The combination can be done at three different levels: observations, normal equations and parameters. This article analyses the differences between the approaches and discusses the possibility of troposphere parameters calculation from a theoretical point of view.

The article generalizes theoretical and practical addition to the components of mathematical processing of geodetic measurements, which are the basis and used to support work in land management and cadastre. The research identifies general components of mathematical processing of geodetic measurements and components which are primarily used in the field of land management and cadastre. Completed investigation of the theoretical and practical foundations of these components and developed theoretical and practical additions improve the results of mathematical processing of geodetic measurements.

The article shows that the rapid technological changes in the field of topographic, geodetic and cadastral activities that have occurred in recent decades, significantly affect the nature and content of work to be performed by future engineers in the field of geodesy and land surveying. The directions of adaptation of the content of geodetic and land surveying education to the needs of the national and world market of engineering services are considered. Global navigation satellite system (GNSS), laser 3D-scanning and operational mapping using unmanned aerial vehicles will have a decisive impact on the development of the industry in the near future. Paper maps are being replaced by multimedia devices that display dynamic map content tailored to a specific consumer. During the study, the student must get acquainted with all the most advanced technologies that will determine the future of the industry in the medium term to be ready for their practical application. A modern university lecture should be designed so that the student can hear only what he or she cannot find on the Internet. The aim of the article is to try to comprehensively generalize and analyse global trends and prospects for the development of topographic and geodetic, cadastral, registration and evaluation activities, as well as to determine on this basis the adaptation of geodetic and land management education to the needs of national and global engineering services.

Local geodetic network is very important in harmonic development of city territory. On the base of the local geodetic network, cadastral and topographic surveying works, engineering geodetic works and executive measurements of newly built buildings and engineering networks are carried out. In the territory of Riga, the local geodetic network was started to create in 1880, and in the course of time, as the city expanded, necessity to have wider reference network emerged. In 2005, in the territory of Latvia, network of continuously working base stations LatPos was launched, which ensured completely new trends in execution of measurements and accuracy reached. One year later, base station network EUPOS-RIGA was launched in the territory of Riga. It can be regarded as consistent part of Riga local geodetic network. The purpose of the research was to state, what are differences between historically used coordinates of points of the local geodetic network, and coordinates that are determined by use of real time corrections of LatPos and EUPOS-RIGA base station network. Measurements were made in the territory of Riga in period from December 2016 until April 2017. In the framework of the research, 61 point of the local geodetic network was inspected and in 38 cases GNSS observations in RTK mode were completed. In the research, catalogues of coordinates of polygonometry points of sixties and eighties were used in order to compare what differences of coordinates existed historically. The main conclusion drawn during the research – historical points of the local geodetic network shall not be used for surveying works of any kind before improvement of them and before they comply with requirements of normative acts.

In order to evaluate the accuracy of the local geodetic network of Jurmala City, in research, comparison of fortyseven selected polygonometry network point coordinates with the obtained data was made by performing measurements by real time cinematic (RTK) method in LatPos base station system. Points were chosen so in order to cover evenly the entire territory of the city. At present, gradual renewal and improvement of the local geodetic network takes place in Jurmala. In Jurmala City, obtaining of data by GNNS data receivers is encumbered by large density of trees. Therefore the local geodetic network in city has very important role in order to ensure performance of geodetic measurements of high quality in the territory of the city. Aim of the research is to evaluate the accuracy of the local geodetic network of Jurmala City. The following tasks have been set for achieving the aim: research of the given problem, visit of the local geodetic network points, performing control measurements, data processing and analysis.

The systemized and methodically arranged according to the principles of geographic information systems set of the most important objects of Lithuanian territory’s geodetic base and topographic databases (GDR10LT) is collected and kept in data storage and covers the whole territory of Lithuania. The purpose of the georeferential base GDR10LT at the scale 1:10 000 is to collect, keep, use, renew and provide data to users. The literature analysis shows that the majority of authors presented studies about data composition and application but they did not analyse their reliability. The aim of the research was to revise the chosen territory of the georeferential base map by the field method and to determine the discrepancies between the situation in the area and in the map as well as the reasons of such discrepancies. It was necessary to verify the data reliability and outdated map information due to changes of the situation. The field research was conducted in three different areas, and the data was processed using tools provided by www.zis.lt. Statistical data analysis was performed using Microsoft Excel software. The object of the research was information depicted in georeferential base map (GDR10LT) of the chosen territories. The following research methods were used: literature analysis, analysis of cartography material, collation of field data, statistical data processing, and interviews. The conclusion can be made that GDR10LT data are reliable; two mistakes were found in the plot of 6407.5 hectares: a navigational obstacle and 800 metres of asphalt cover were not marked. Other determined discrepancies covered the territory of 17.46 hectares. The outdated map information was found. The marking of settlements generally were mismatched because of many new buildings in the area that were not mapped. Therefore GDR10LT should be updated more often in accordance with ORT10LT data.

Railway tracks require more thorough maintenance and analysis than regular roads for cars. Defects are here noticed and recorded by using special equipment. Construction of railway roads and their exploitation requires optimal accuracy and monitoring of surveying. It is related to maximum allowed speed of trains, the environment, transport and human safety. In order to highlight complex problems of railway road exploitation, the evaluation of railway roads was conducted. Problem areas of railway maintenance were identified. Their monitoring needs to be improved by applying geodetic devices for surveying. Comparing analogous surveying conducted using EM140 machine with that of geodetic equipment, one can see the advantage of geodetic surveying. Technical gaps in the surveying process, data storage and procession were evaluated as well. It was discovered that maintenance and monitoring works should be pursued more frequently using high accuracy geodetic equipment.