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Meteorology monitoring of the precipitable water vapour distribution in the atmosphere based on operational GNSS data processing at reference station network ZAKPOS
2014
Savchuk, S., Lviv Polytechnic National Univ. (Ukraine) | Kablak, N., Uzhhorod National Univ. (Ukraine) | Kalynych, I., Uzhhorod National Univ. (Ukraine) | Reity, O., Uzhhorod National Univ. (Ukraine)
Remote monitoring of the atmosphere is designed to obtain information about the state of the atmosphere. The principle of the remote monitoring system of the atmosphere is based on the registration and processing of spacecraft radio signals of the Global Navigation Satellite Systems (GNSS). The wet tropospheric delay component of the electromagnetic signal (Δρ sup(tropo) sub(w)), which is derived from the GNSS observations data analysis, is used to calculate the water vapour content in the atmosphere. It is well known, that this parameter is critical to meteorologists, because the water vapour content in the atmosphere is a key parameter in the construction of numerical weather modelling. In this article the IWV - Integrated Water Vapour has been estimated and the expected accuracy of its determination on the basis of the operational GNSS data processing from reference station network ZAKPOS and the results of aerologic sensing of the atmosphere are given.
显示更多 [+] 显示较少 [-]Research of national geodetic network elevations at Eastern part of Latvia
2014
Celms, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Ratkevics, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Rusins, J., Latvia Univ. of Agriculture, Jelgava (Latvia)
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.
显示更多 [+] 显示较少 [-]Status of the polygonometric network for Kaunas city and region
2014
Kriauciunaite–Neklejonoviene, V., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania) | Rekus, D., Aleksandras Stulginskis Univ., Akademija, Kauno reg. (Lithuania)
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.
显示更多 [+] 显示较少 [-]Global navigation satellite systems technical solutions developments of farmland processing in Latvia
2015
Ratkevics, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Celms, A., Latvia Univ. of Agriculture, Jelgava (Latvia) | Baumane, V., Latvia Univ. of Agriculture, Jelgava (Latvia)
Global Navigation Satellite System (GNSS) services in Latvia nowadays provide not only for a variety of navigation and surveying needs, but also they are used in agricultural production. The time period when satellite navigation systems equipment and services in agricultural businesses appeared in Latvia and were treated as objects of interest and research has passed. GNSS equipment and enabling modules are purchased, installed and used in agricultural equipment extending their capabilities. A growing number of entrepreneurs provide for this service segment. In the publication of 2014, the authors pointed out that a preparatory and investigation phase in using precision farming systems (including GNSS technology related to them) in Latvia has come to an end transforming into massive practical implementation in the process of agricultural business. The analysis of the obtained information confirmed that during the last year further satellite navigation technology usage in agricultural machinery has grown from simple and approximate level usage to high accuracy and stability navigation services. Growth dynamics and its further development forecasted earlier by the authors coincided with the last year’s actual development indicators of a stable and growing demand for global navigation system services for farming machinery and technical solutions for their user segment. The aim of the article is to justify the forecast expressed in the last year’s publication regarding the increase of the use of precision farming systems thus confirming the fact that their application has moved from a research phase to massive practical implementation and operation in agricultural production.
显示更多 [+] 显示较少 [-]Spatial pattern of residential densification in housing submarket of a traditional urban area
2021
Mohammed, J.K., Federal Polytechnic, Bida (Nigeria) | Sulyman, A.O., Federal Univ. of Technology, Minna (Nigeria) | Aliyu, A.A., Federal Polytechnic, Bida (Nigeria)
The study aimed at examining the spatial pattern of residential densification in housing submarkets of Bida, an ancient traditional town in Nigeria. The study adopted the 2015 standard residential density of Niger State Urban Development Board to determine the level of residential density and occupancy rates of the various submarkets of the town. The study also adopted primary method of data collection through the use of satellite images, handheld GPS and georeferencing of demarcated areas and the buildings, using point features and vector approach in ArcGIS environment to achieve the area coverage, number of buildings and buildings per hectare (ha) in the housing submarkets. The finding of the study reveals that in 2008 Town housing submarket has the highest area coverage, followed by the Project Quarters and then GRA, but in terms of residential density, four housing submarkets of Town, Rahmatu Dangana, Gbazhi and Wadata have high densities above the other seven submarkets. The study further reveals that in the year 2013, additional eight housing submarkets have high residential densities, GRA medium density while Eyagi and Prject Quarters had low densities respectively. It was therefore recommended that there is the need for rational densification (planned densification) for urban development in order to check the increasing unplanned residential density that reduces the green and open spaces in urban environment.
显示更多 [+] 显示较少 [-]Investigation of the accuracy of spatial data of the GRPK building layer in the territory of Lithuania
2022
Salkauskiene, Vilma | Gudritiene, Daiva | Abalikstiene, Edita
Spatial data is constantly evolving, and the accuracy of spatial data is constantly changing. The latest GRPK and orthophotographic map were used in the study. Accuracy is also affected by technological advances, which are driven by improvements in working methods, which include the development of work tools and the development of data sets that contain structured data. The data contained in the data sets are determined by a variety of methods, such as field measurements (GPNS receiver or tacheometer) and analysis of digital photographic images, which are determined using aircraft or satellite systems. The determined data is processed with the help of specialized software, which is selected depending on its functionality and capabilities, and with the help of which the determined data is processed as accurately as possible. Accurate spatial data in densely populated areas makes it easier to carry out planning and design work correctly. The study is performed to determine the accuracy of the coordinates of the selected structures using remote methods. The more similar studies are conducted, the more confident the GRPK data generated remotely will be of the required accuracy, reliability, and applicability to planning, forecasting, and other important tasks. The article compares geodetic measurements and GRPK data and geodetic measurements and ORT10LT data, identifies coordinate differences, the size of the discrepancy and its average, and calculates the root mean square error. The object of the research is spatial and cartographic data of different buildings. The aim of the research is to determine and evaluate the accuracy of the coordinates obtained using remote sensing methods.
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