GEODESIC METHODS FOR CREATION OF UNIQUE GEOINFORMATION SPACE

Modern geodesic support is an integral and essential element of the process of collecting spatial information. The article considers geodesic methods for creating a unique geoinformation space: digitization of cartographic materials, ground survey methods (electronic total stations, 3D laser scanning), remote sensing and methods of the global navigation satellite systems GLONASS and GPS. The article also contains recommended conversion options between the coordinate systems SK-95 and GSK-2011. A comparative analysis of the surveyed geodesic methods for geodata col-lection was carried out. Russian and foreign markets of specialized software for processing geodata are considered, appropriate conclusions are made.

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The Etruscans in 3D: From Space to Underground

Geoinformatics FCE CTU ◽

10.14311/gi.6.35 ◽

2011 ◽

Vol 6 ◽

pp. 283-290 ◽

Cited By ~ 8

Author(s):

Fabio Remondino ◽

Alessandro Rizzi ◽

Belen Jimenez ◽

Giorgio Agugiaro ◽

Giorgio Baratti ◽

...

Keyword(s):

Cultural Heritage ◽

Information And Communication Technologies ◽

Laser Scanning ◽

Information Science ◽

Geographic Information ◽

Global Navigation Satellite Systems ◽

Satellite Systems ◽

Heritage Sites ◽

Museum Exhibitions ◽

Global Navigation Satellite

eomatics and Geoinformatics deal with spatial and geographic information, 3D surveying and modeling as well as information science infrastructures. Geomatics and Geoinformatics are thus involved in cartography, mapping, photogrammetry, remote sensing, laser scanning, Geographic Information Systems (GIS), Global Navigation Satellite Systems (GNSS), geo-visualisation, geospatial data analysis and Cultural Heritage documentation. In particular the Cultural Heritage field can largely benefit from different Information and Communication Technologies (ICT) tools to make digital heritage information more informative for documentation and conservation issues, archaeological analyses or virtual museums. This work presents the 3D surveying and modeling of different Etruscan heritage sites with their underground frescoed tombs dating back to VII-IV century B.C.. The recorded and processed 3D data are used, beside digital conservation, preservation, transmission to future generations and studies purposes, to create digital contents for virtual visits, museum exhibitions, better access and communication of the heritage information, etc.

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GNSS Interference Environment in Malaysia: A Case Study

Journal of Engineering Technology and Applied Physics ◽

10.33093/jetap.2021.3.1.3 ◽

2021 ◽

Vol 3 (1) ◽

pp. 13-16

Author(s):

Ooi Wei Han ◽

Shahrizal Ide Moslin ◽

Wan Aminullah

Keyword(s):

Public Awareness ◽

Essential Element ◽

Global Navigation Satellite Systems ◽

Space Technology ◽

Local Study ◽

Satellite Systems ◽

Wide Range ◽

Global Navigation Satellite ◽

Significant Interference

Global Navigation Satellite Systems or GNSS is a space technology that has become an essential element nowadays for positioning, navigation & timing (PNT) with wide range of applications in many civilian sectors as well as across military. The reliability, accuracy and availability of GNSS are highly important especially for critical and precise positioning applications. However, the signals from space are weak and it can be easily blocked, disrupted or compromised by several other threats including intentional and unintentional interferences or jamming. GPS jammer is widely available off the shelf with an affordable price and capable of interfering the GPS signal, and many authorities worldwide have raised concerns and a lot of efforts and research have been put in place to reduce and mitigate the threats. In Malaysia, understanding and countering threats to GNSS/GPS based applications will be a new and unfamiliar discipline for public and organizations. This study intended to provide an overview of the GNSS interferences environment in a local study area, in terms of interference type and the number of activity pattern that were detected. A system called Detector V1 has been used in this study. The result showed that significant interference cases happened in the study area and some of the high power interferences may impact GNSS tracking and precision of the positioning output. The role objective of having this done is to create a public awareness regarding the threat of GNSS interferences to the local users. The content also includes the proposed initiative to overcome the issue.

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Accuracy Assessment of Mobile Laser Scanning Elevation Data in Different Vegetation Areas

Proccedings of 10th International Conference "Environmental Engineering" ◽

10.3846/enviro.2017.202 ◽

2017 ◽

Author(s):

Kaupo Kokamägi ◽

Natalja Liba ◽

Kristo Must ◽

Martin Sirk

Keyword(s):

Laser Scanning ◽

Accuracy Assessment ◽

Objective Assessment ◽

Global Navigation Satellite Systems ◽

Satellite Systems ◽

Sparse Vegetation ◽

Aerial Laser Scanning ◽

Elevation Data ◽

Global Navigation Satellite ◽

Ground Profile

Due to the overall development of technology, laser scanning has reached a new level. During the last decade, all the different technologies necessary for mobile laser scanning, have been developed. Due to the fact that mobile laser scanning brings the need to process very large amounts of data, development of computers and software is also very important. The aim of current research was to assess the accuracy of mobile laser scanning elevation data in different vegetation areas and to explore if mobile laser scanning could be used as an alternative to aerial laser scanning. This article only covers the data collecting, processing and accuracy assessment aspects of the research. Data used in current study was collected in summer of 2015, during mobile laser scanning of Põltsamaa-Kärevere section of E263 route (Tallinn-Tartu-Võru-Luhamaa). Three smaller, differently vegetated, sections were picked from the large project to study the accuracy of elevation data. For accuracy assessment, the mobile laser scanning elevation data was compared to the checkpoints measured with GNSS (Global Navigation Satellite Systems) device. Ground profiles were drawn based on mobile laser scanning data. For objective assessment, accuracy of mobile laser scanning elevation data was compared to accuracy of ground profile elevation data and aerial laser scanning elevation data. The study found that the RMSE (Root Mean Square Error) in the I section, which was a field vegetated with 1 metre high crop, was 0,98 metres. RMSE in the II section, which was a pasture with low and sparse vegetation, was 0,23 metres. RMSE in the III section, which contained a bushy ditch and a field behind it, was 0,61 metres. Results show that the accuracy of mobile laser scanning elevation data depends substantially on the density of vegetation in scanned areas and that drawing ground profiles reduced the RMSE of mobile laser scanning elevation data. Results show that the accuracy of mobile laser scanning elevation data depends substantially on the density of vegetation in scanned areas. On this basis it can be concluded, that the most reasonable time to conduct mobile laser scanning would be during a season, when vegetation is the sparsest. It can also be concluded that drawing ground profiles makes mobile laser scanning data more accurate.

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Experimental Assessment of UWB and Vision-Based Car Cooperative Positioning System

Remote Sensing ◽

10.3390/rs13234858 ◽

2021 ◽

Vol 13 (23) ◽

pp. 4858

Author(s):

Andrea Masiero ◽

Charles Toth ◽

Jelena Gabela ◽

Guenther Retscher ◽

Allison Kealy ◽

...

Keyword(s):

Essential Element ◽

Wide Band ◽

Global Navigation Satellite Systems ◽

Learning Tools ◽

Satellite Systems ◽

Cooperative Positioning ◽

Performance Improvements ◽

Gnss Measurements ◽

Global Navigation Satellite ◽

Gnss Data

The availability of global navigation satellite systems (GNSS) on consumer devices has caused a dramatic change in every-day life and human behaviour globally. Although GNSS generally performs well outdoors, unavailability, intentional and unintentional threats, and reliability issues still remain. This has motivated the deployment of other complementary sensors in such a way that enables reliable positioning, even in GNSS-challenged environments. Besides sensor integration on a single platform to remedy the lack of GNSS, data sharing between platforms, such as in collaborative positioning, offers further performance improvements for positioning. An essential element of this approach is the availability of internode measurements, which brings in the strength of a geometric network. There are many sensors that can support ranging between platforms, such as LiDAR, camera, radar, and many RF technologies, including UWB, LoRA, 5G, etc. In this paper, to demonstrate the potential of the collaborative positioning technique, we use ultra-wide band (UWB) transceivers and vision data to compensate for the unavailability of GNSS in a terrestrial vehicle urban scenario. In particular, a cooperative positioning approach exploiting both vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) UWB measurements have been developed and tested in an experiment involving four cars. The results show that UWB ranging can be effectively used to determine distances between vehicles (at sub-meter level), and their relative positions, especially when vision data or a sufficient number of V2V ranges are available. The presence of NLOS observations is one of the principal factors causing a decrease in the UWB ranging performance, but modern machine learning tools have shown to be effective in partially eliminating NLOS observations. According to the obtained results, UWB V2I can achieve sub-meter level of accuracy in 2D positioning when GNSS is not available. Combining UWB V2I and GNSS as well V2V ranging may lead to similar results in cooperative positioning. Absolute cooperative positioning of a group of vehicles requires stable V2V ranging and that a certain number of vehicles in the group are provided with V2I ranging data. Results show that meter-level accuracy is achieved when at least two vehicles in the network have V2I data or reliable GNSS measurements, and usually when vehicles lack V2I data but receive V2V ranging to 2–3 vehicles. These working conditions typically ensure the robustness of the solution against undefined rotations. The integration of UWB with vision led to relative positioning results at sub-meter level of accuracy, an improvement of the absolute positioning cooperative results, and a reduction in the number of vehicles required to be provided with V2I or GNSS data to one.

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GNSS-and-GIS based android integration of mobile based virtual guide application ExpLahore for walled city Lahore, Pakistan

Natural and Applied Sciences International Journal (NASIJ) ◽

10.47264/idea.nasij/2.1.2 ◽

2021 ◽

Vol 2 (1) ◽

pp. 12-25

Author(s):

Aaysha Rahim ◽

Najam Abbas Naqvi

Keyword(s):

Spatial Information ◽

Global Navigation Satellite Systems ◽

Android Application ◽

Security Risks ◽

Precise Location ◽

Precise Position ◽

Satellite Systems ◽

Adobe Illustrator ◽

Exact Position ◽

Global Navigation Satellite

The expansion of technology by utilizing Global Navigation Satellite Systems (GNSS) integrated with Geographic Information System (GIS) has made life much easier and handy. Global interactions have given birth to tourism and intra-culture programs. Many foreigners as well as local tourists prefer to explore the sites on their own instead of a guide, this is quite adventurous but can be tedious too and brings along a lot of security risks. This research is based on design and development of an android application considering “Walled City, Lahore, Pakistan”. The application will help tourist geotag their information. This application has been developed with the fact to provide precise position through GNSS, the coordinates have been refined using ArcGIS and QGIS and placed in application using Android Studio and Adobe Illustrator. GIS allowed creating interactive queries, analyzing spatial information and map creation, shape file extraction and 99% precise coordinates than maps we use. In travelling world, geotagging is a great and trending feature that allows user to share their exact position. The application will locate user’s coordinates (Latitude and Longitude), current satellite count, precision, altitude, time and day. The guidance application helps user find the correct possible route to the monuments of walled City, Lahore. Information and precise location of 14 place groups of Lahore city, as well as precise route to them is also a feature of the application.

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Assessment of Smartphone Positioning Data Quality in the Scope of Citizen Science Contributions

Mobile Information Systems ◽

10.1155/2017/4043237 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 4

Author(s):

Angel J. Lopez ◽

Ivana Semanjski ◽

Sidharta Gautama ◽

Daniel Ochoa

Keyword(s):

Data Quality ◽

Survey Methods ◽

Travel Behaviour ◽

Global Navigation Satellite Systems ◽

Mobility Patterns ◽

Satellite Systems ◽

Mobility Behaviour ◽

Global Navigation Satellite ◽

Behaviour Data

Human travel behaviour has been addressed in many transport studies, where travel survey methods have been widely used to collect self-reported insights of daily mobility patterns. However, since the introduction of Global Navigation Satellite Systems (GNSS) and more recently smartphones with built-in GNSS, researchers have adopted these ubiquitous devices as tools for collecting mobility behaviour data. Although most studies recognize the applicability of this technology, it still has limitations. These are rarely addressed in a quantified manner. Often the quality of the collected data tends to be overestimated and these errors propagate into the aggregated results providing incomplete knowledge of the levels of confidence of the results and conclusions. In this study, we focus on the completeness aspects of data quality using GNSS data from four campaigns in the Flanders region of Belgium. The empirical results are based on mobility behaviour data collected through smartphones and include more than 450 participants over a period of twenty-nine months. Our findings show which transport mode is affected the most and how land use affects the quality of the collected data. In addition, we provide insights into the time to first fix that can be used for a better estimation of travel patterns.

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The stochastic model for Global Navigation Satellite Systems and terrestrial laser scanning observations: A proposal to account for correlations in least squares adjustment

Journal of Applied Geodesy ◽

10.1515/jag-2018-0019 ◽

2019 ◽

Vol 13 (2) ◽

pp. 93-104 ◽

Cited By ~ 7

Author(s):

Gael Kermarrec ◽

Ingo Neumann ◽

Hamza Alkhatib ◽

Steffen Schön

Keyword(s):

Least Squares ◽

Laser Scanning ◽

Global Navigation Satellite Systems ◽

Deformation Analysis ◽

Navigation Satellite ◽

Unknown Parameters ◽

Satellite Systems ◽

Unbiased Test ◽

Global Navigation ◽

Global Navigation Satellite

Abstract The best unbiased estimates of unknown parameters in linear models have the smallest expected mean-squared errors as long as the residuals are weighted with their true variance–covariance matrix. As this condition is rarely met in real applications, the least-squares (LS) estimator is less trustworthy and the parameter precision is often overoptimistic, particularly when correlations are neglected. A careful description of the physical and mathematical relationships between the observations is, thus, necessary to reach a realistic solution and unbiased test statistics. Global Navigation Satellite Systems and terrestrial laser scanners (TLS) measurements show similarities and can be both processed in LS adjustments, either for positioning or deformation analysis. Thus, a parallel between stochastic models for Global Navigation Satellite Systems observations proposed previously in the case of correlations and functions for TLS range measurements based on intensity values can be drawn. This comparison paves the way for a simplified way to account for correlations for a use in LS adjustment.

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