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1

Application of Terrestrial Laser Scanning and Global Navigation Satellite System in the Mining Area

Pham Van Chung, Lipecki Tomasz, Vo Ngoc Dung

Inżynieria Mineralna

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2024

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Vol. 2, no. 1

55--61

EN

Terrestrial Laser Scanning and Global Navigation Satellite System technologies are increasingly prevalent in geodetic mapping work, playing a significant role in mine surveying tasks such as drawing maps for volume calculation, monitoring displacement, and deformation of mine surfaces and structures above mine tunnels. Currently, there are many studies on the application of these technologies in various aspects of mine surveying work. This paper will synthesize these studies to evaluate the effectiveness of applying GNSS and TLS technologies in mining surveying. The authors has reviewed 44 papers/projects in recent years and found that these technologies are developing rapidly, with the accuracy of coordinate and altitude measurement increasingly improving to approximately millimeters in both horizontal and vertical directions.

PL

Technologie naziemnego skanowania laserowego (TLS) i globalnego systemu nawigacji satelitarnej (GNSS) są coraz bardziej powszechne w pracach związanych z kartowaniem geodezyjnym, odgrywając znaczącą rolę w zadaniach geodezyjnych w kopalniach, takich jak two-rzenie map do obliczania objętości, monitorowanie przemieszczeń i deformacji powierzchni i konstrukcji nad wyrobiskami górniczymi. Obecnie prowadzonych jest wiele badań nad zastosowaniem tych technologii w różnych aspektach prac geodezyjnych w kopalniach. W artykule dokonana została synteza tych badań w celu oceny efektywności zastosowania technologii GNSS i TLS w górnictwie. Autorzy dokonali przeglądu 44 artykułów/projektów z ostatnich lat i stwierdzają, że technologie te bardzo szybko się rozwijają, a dokładność pomiaru współrzędnych i wysokości wzrasta do poziomu pojedynczych milimetrów zarówno w kierunku poziomym, jak i pionowym.

2

Model of the signal of the Galileo Satellite Navigation System

Džunda M., Čikovský S., Melniková L.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

51--59

EN

This article presents an analysis of the Galileo E1 signal and its sensitivity to different types of interference. The research involved modeling white noise, chaotic impulse interference, and narrowband interference and the effects of these interfering signals on the E1 signal. Based on the available information, spectral structures were created for the mentioned types of interference, and subsequently, these interferences were integrated into the E1 signal in the Matlab program environment. A Kallman filter was used to filter out white noise from the additive mixture of the E1 signal and white noise. The research aimed to analyze the influence of white noise, chaotic impulse interference, and narrowband interference on the spectral power density of the E1 signal. The results of this work can be used in the design of robust receivers and signal structures capable of withstanding these types of interference.

3

Comparative analysis of unmanned aerial vehicles used in photogrammetric surveys

Specht M., Widźgowski S., Stateczny A., Specht C., Lewicka O.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 2

433--443

EN

There are many manufacturers on the market offering various types of Unmanned Aerial Vehicles (UAV). The multitude of drones available on the market means that the choice of a UAV for a specific application appears to be a decision problem to be solved. The aim of this article is a comparative analysis of drones used in photogrammetric surveys. The criteria for evaluating the UAVs were: availability and product support, payload (min. 5 kg), price (PLN 100,000), as well as space available for measurement modules. These are the requirements that must be met for the implementation of the INNOBAT project, the aim of which is to develop an integrated system using autonomous unmanned aerial and surface vehicles, intended for bathymetric monitoring in the coastal zone. The comparative analysis of drones was based on 27 companies producing UAV. Based on the analysis, 6 drones that met the project requirements were selected. They were: Aurelia X6 Pro, Aurelia X8 Standard LE, DroneHexa AG, FOX-C8 XT, Hercules 10 and Zoe X4. Selected UAVs differ from each other, among others, in the number of rotors, flight duration and resistance to weather conditions. Individual characteristics of drones may have a different rank depending on their application, therefore the selection of UAVs should be made after prioritisation criteria of a given project.

4

A PPP baseline approach for bridge passing

Lass C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 1

33--40

EN

Global Navigation Satellite Systems (GNSS) are increasingly used as the main source of Positioning, Navigation and Timing (PNT) information for inland water navigation. In order to enable automated driving and facilitate driver assistant functions, it becomes of crucial importance to ensure high reliability and accuracy of the GNSS-based navigation solution, especially in challenging environments. One challenging phase of inland waterway navigation is bridge passing which leads to non-line-of-sight (NLOS) effects such as multipath and loss of tracking. This work presents a Precise Point Positioning (PPP) based algorithm in a two-antenna system where one antenna is at the bow and the other is at the stern. Additionally, gyroscope data from an IMU is used. In contrast to a separated position calculation of the two antennas, only one antenna position is estimated and the other is derived from the baseline between the antennas. This allows for accurate positioning even if one antenna does not receive any GNSS measurements. The presented scheme is evaluated using real measurement data from an inland water scenario with multiple bridges. In comparison with a standard PPP scheme as well as an RTK algorithm, the presented approach shows clear advantages in challenging scenarios.

5

Architecture of positioning and tracking solutions for maritime applications

Ilcev S.D.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2022

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Vol. 16 No. 3

481--489

EN

This paper discusses the current and new satellite transponders for global tracking and detecting of oceangoing ships, assets, crew, passengers and any moving objects at sea for enhanced vessels traffic control and management. These transponders are able to monitor all maritime assets and to improve safety, security of movements and collision avoidance, especially during very bad weather conditions and visibility. By deployment of the Global Navigation Satellite System (GNSS) in integration with Inmarsat, Iridium and other satellite systems in one unit with antenna, it is possible to provide reliable positioning and tracking solutions for civilian maritime, other mobiles and personnel at different Radio Frequency (RF) bands. The existing and forthcoming space and ground segment for positioning and tracking solutions as a modern Satellite Asset Tracking (SAT) onboard ships, and other relating systems are discussed and benefits of these new technologies and solution for improved positioning and tracking are explored.

6

Support Vector Regression model to predict TEC for GNSS signals

Sivakrishna Kondaveeti, Ratnam Devanaboyina Venkata, Sivavaraprasad Gampala

Acta Geophysica

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2022

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Vol. 70, no 6

2827--2836

EN

Ionospheric Total Electron Content (TEC) predominantly affects the radio wave communication and navigation links of Global Navigation Satellite Systems (GNSS). The ionospheric TEC exhibits a complex spatial–temporal pattern over equatorial and low latitude regions, which are difficult to predict for providing early warning alerts to GNSS users. Machine Learning (ML) techniques are proven better for ionospheric space weather predictions due to their ability of processing and learning from the available datasets of solar-geophysical data. Hence, a supervised ML algorithm such as the Support Vector Regression (SVR) model is proposed to predict TEC over northern equatorial and low latitudinal GNSS stations. The vertical TEC data estimated from GPS measurements for the entire 24th solar cycle period, 11 years (2009–2019), is considered over Bengaluru and Hyderabad International GNSS Service (IGS) stations. The performance of the proposed SVR model with kernel Gaussian or Radial Basis Function (RBF) is evaluated over the two selected testing periods during the High Solar Activity (HSA) year, 2014 and the Low Solar Activity (LSA) year, 2019. The proposed model performance is compared with Neural Networks (NN) model, and International Reference Ionosphere (IRI-2016) model during both LSA and HSA periods. It is noticed that the proposed SVR model has well predicted the VTEC values better than NN and IRI-2016 models. The experimental results of the SVR model evidenced that it could be an effective tool for predicting TEC over low-latitude and equatorial regions.

7

The Russian ALFA system in the context of thedevelopment of radionavigation in the 21st century

Felski Andrzej

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2021

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Vol. 15 No. 4

723--728

EN

For nearly the entire post-World War II period, naval and air navigation relied primarily on ground-based radionavigation systems. However, the spontaneous development of satellite systems gradually led to their disappearance. They are currently used partly in air operations and marginally in maritime navigation in some areas around Asia, in Russia and in the Middle East. However, at the beginning of the 21st century, the threat of effective interference with satellite systems began to be raised, which led to an increased interest in restoring or upgrading ground-based systems as backup systems in the Western world. In this context, the approach of Russia is interesting, as it is associated with the vast majority of deliberate GPS interference. There are reports in the world literature that various ground-based radionavigation systems operating in Russia are still observed. The article analyses, on the basis of the few available sources, information on the ALFA system, about which the least is known, and there are many indications that it is ready for use.

8

Modelling GPS positioning performance in Northwest Passage during extreme space weather conditions

Špoljar D., Jukić O., Sikirica N., Lenac K., Filjar R.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2021

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Vol. 15 No. 1

165--169

EN

New shipping routes are emerging as a result of iceberg melting in polar regions, allowing for more efficient transport of people and goods. Opening of the Northwest Passage, the maritime route connecting Pacific Ocean with Atlantic Ocean through Arctic region, is considered such a development. The increasing transport exploitation of the Northwest Passage requires the quality assessment of maritime navigation aids for compliance with the established requirements. Here we contribute to the subject with addressing the polar commercial-grade GPS positioning performance in the Northwest Passage in the extreme positioning environment conditions during the massive 2003 space weather storm, a space weather event similar to the Carrington Storm of 1859, the largest space weather event recorded. The GPS positioning environment in the Northwest Passage during the Carrington-like storm in 2003 was reconstructed through the GNSS SDR receiver-post processing of the experimental GPS observations. The raw GPS dual-frequency pseudoranges and navigation messages were collected at the International GNSS Service (IGS) reference station at Ulukhaktok, Victoria Island, Canada. Pseudorange processing and GPS position estimation were performed in three scenarios of pre-mitigation of the ionospheric effects, known as the single major contributor GPS positioning error: (i) no corrections applied, (ii) Klobuchar-based corrected GPS positioning, and (iii) dual-frequency corrected GPS positioning. Resulting GPS positioning error vectors were derived as positioning error residuals from the known reference station position. Statistical properties of the northing, easting, and vertical components of the GPS positioning error vector were analyzed with a software developed in the R environment for statistical computing to select suitable methods for the GPS positioning error prediction model development. The analysis also identified the most suitable theoretical fit for experimental statistical distributions to assist the model development. Finally, two competitive GPS positioning error prediction models were developed, based on the exponential smoothing (reference) and the generalized regression neural networks (GRNN) (alternative) methods. Their properties were assessed to recommend their use as mitigation methods for adverse massive space weather effects in polar regions.

9

Low bandwidth network-RTK correction diissemination for high accuracy maritime navigation

Alissa S., Håkansson M., Henkel P., Mittmann U., Hüffmeier J., Rylander R.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2021

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Vol. 15 No. 1

171--179

EN

More than half of the incidents reported to EMSA relate to nautical events such as collision, groundings and contacts. Knowledge of accurate and high-integrity positioning is therefore not only a need for future automated shipping but a base for today’s safe navigation. Examples on accidents include Ever Given in the Suez Canal and HNoMS Helge Ingstad in Norway. A Network-RTK (NRTK) service can be used as an augmentation technique to improve performance of shipborne GNSS receivers for future positioning of manned and unmanned vessels in restricted areas, such as port areas, fairways, and inland water ways. NRTK service providers generate RTK corrections based on the observations of networks of GNSS reference stations which enables the users to determine their position with centimeter accuracy in real-time using a shipborne GNSS receiver. Selection of appropriate communication channels for dissemination of NRTK corrections data is the key to a secure positioning (localization) service. In PrePare-Ships project, the modern maritime communication system VDES (VHF Data Exchange System) is proposed to distribute SWEPOS (NRTK in Sweden) correction data to shipborne positioning modules. VDES is a very reliable technique and it is compatible with most onboard functionalities. In order to minimize the impact on the overall VDES data capacity in a local area, NRTK correction data shall only occupy a single VDES slot with a net capacity of 650 bytes. Update rates may vary but are preferably at 1Hz. However, NRTK correction data size changes instantly, depending on the number of visible GNSS satellites, and the data rate can therefore sometimes reach in excess of 1000 byte/s. In this study, a smart technique is proposed to reduce size of NRTK correction data to instantly adapt with the VDES requirements by choosing a combination of specific signals, satellites or even constellations such that the data rate is not more than 650 byte/s, and at the same time it achieves optimal positioning performance with the accuracy required by the PrePare-Ships project application.

10

Analysis of aircraft equipment requirements to conduct RNP APCH approach operation

Kwasiborksa Anna, Gładyś Sylwester, Banaszek Krzysztof, Manewrowski Jerzy, Roś Maciej

Systemy Logistyczne Wojsk

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2021

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Vol. 55, no. 2

101--120

PL

Ruch statków powietrznych jest ciągle analizowany z uwagi na problematykę pojemności przestrzeni powietrznej i przepustowości portów lotniczych. Ważnym obszarem jest podejście do lądowania statków powietrznych na dane lotnisko z wykorzystaniem pomocy nawigacyjnych. Urządzenia i systemy nawigacyjne są dostosowywane do wymagań prawnych organizacji europejskich i międzynarodowych. Do użytku operacyjnego podczas podejść do lądowania dopuszczono możliwość korzystania z systemu GNSS wraz z odpowiednią augmentacją (ABAS lub SBAS) określoną jako podejścia RNP APCH. Ich wprowadzenie skutkowało w pojawieniu się szeregu korzyści. Autorzy podjęli się analizy wymagań wyposażenia pokładowego statków powietrznych niezbędnego do wykonywania podejść RNP APCH. Celem naukowym jest ocena wyposażenia pokładowego RNAV statków powietrznych na przykładzie trzech przewoźników lotniczych (stan na grudzień 2018r.). Weryfikacji poddano hipotezę szacując wysoki stopień wyposażenia pokładowego RVAV statków powietrznych. Zastosowano metodę analizy wykorzystując aplikację CNS Dashboard udostępnionej przez Eurocentów. Wskazuje ona zadeklarowane możliwości nawigacyjne samolotów na podstawie planów lotu ICAO przesyłanych przez przewoźników do Network Managera skorelowanych z bazą danych statków powietrznych PRISME Fleet 2. W wyniku przeprowadzonej analizy, można zauważyć, że prawie wszystkie badane statki powietrzne miały wymaganą certyfikację do przeprowadzania podejść RNP APCH z użyciem systemu ABAS (96% badanych). Z drugiej strony żaden z samolotów nie miał wymaganego wyposażenia do wykorzystywania systemu SBAS podczas lądowania. Na podstawie badania dokumentów i obserwacji obszaru badawczego można stwierdzić, że przewoźnicy lotniczy coraz częściej wyposażają swoje statki powietrzne w wymagane moduły podejściach do lądowania typu RNP APCH.

EN

Aircraft traffic is constantly analyzed due to the issues of airspace and airport capacity. An important area is the approach to landing of aircraft at a given airport with the use of navigation aids. Navigation devices and systems are adapted to the legal requirements of European and international organizations. The use of the GNSS system with appropriate augmentation (ABAS or SBAS) defined as RNP APCH approaches is authorized for operational use during landing approaches. Their introduction resulted in the emergence of a number of benefits. The authors analyzed the requirements of the aircraft on-board equipment necessary to perform RNP APCH approaches. The research goal is to evaluate the RNAV on-board equipment of aircraft on the example of three air carriers (as of December 2018). The hypothesis was verified by estimating the high level of on-board RVAV equipment of the aircraft. The method of analysis was applied using the CNS Dashboard application provided by Eurocontrol. It indicates the declared navigational capabilities of airplanes based on ICAO flight plans sent by carriers to the Network Manager correlated with the PRISME Fleet 2 aircraft database. using the ABAS system (96% of respondents). On the other hand, none of the aircraft had the required equipment to use SBAS during landing. Based on the examination of documents and observation of the research area, it can be concluded that air carriers more and more often equip their aircraft with the required modules of RNP APCH landing approaches.

11

Broadcast ionospheric delay correction algorithm using reduced order adjusted spherical harmonics function for single frequency GNSS receivers

Abhigna M. S. R., Sridhar M., Harsha P. Babu Sree, Krishna K. Siva, Ratnam D. Venkata

Acta Geophysica

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2021

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Vol. 69, no. 1

335--351

EN

Single-frequency Global Navigation Satellite System (GNSS) users require an efcient ionospheric delay correction model for improving their positional accuracy. GPS satellite range signals undergo time delay through the inhomogeneous and dynamic state of the ionosphere. The ionospheric delay is inverse proportional to the signal frequency square due to the dispersive nature of the ionospheric medium. There is a need for aid regional ionospheric broadcast correction model that is necessary for low-latitude ionospheric conditions. In this paper, a reduced order adjusted spherical harmonics function (ROASHF) ionospheric broadcast correction model with order and degree 2 is proposed for the Indian region. A dense GPS receiver network of 14 GPS receivers over the Indian region is analyzed to derive nine ROASHF broadcast coefcients. The performance of the proposed ionospheric broadcast correction model is compared with Klobuchar, NeQuickG, BDS-2, CODEKlob, and CODEGIM TEC models during March and September equinox and June and December solstice days in 2015 and 2016. The mean root mean square error (RMSE) of ROASHF, Klobuchar, NeQuickG, BDS-2, CODEKlob, and CODEGIM TEC models is 7.13 TECU, 9.52 TECU, 15.52 TECU, 11.44 TECU, 13.47 TECU, and 11.97 TECU, respectively. The results demonstrated that the proposed ROASHF ionospheric broadcast model could better predict the ionospheric delays for single-frequency GNSS users. The proposed ionospheric broadcast model is suitable for the Indian regional navigation system known as Navigation with Indian Constellation (NavIC).

12

VR teleoperation to support a GPS-free positioning system in a marine environment

Lager M., Topp E. A., Malec J.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2020

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Vol. 14. no. 4

789--798

EN

Small autonomous surface vehicles (ASV) will need both teleoperation support and redundant positioning technology to comply with expected future regulations. When at sea, they are limited by a satellite communication link with low throughput. We have designed and implemented a graphical user interface (GUI) for teleoperation using a communication link with low throughput, and one positioning system, independent of the Global Positioning System (GPS), supported by the teleoperation tool. We conducted a user study (N=16), using real-world data from a field trial, to validate our approach, and to compare two variants of the graphical user interface (GUI). The users experienced that the tool gives a good overview, and despite the connection with the low throughput, they managed through the GUI to significantly improve the positioning accuracy.

13

Mobile radio beacons in coastal reserved navigation system for ships

Kelner J. M., Ziółkowski C.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2020

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Vol. 14. no. 3

603--610

EN

At the turn of the 20th and 21st centuries, Global Navigation Satellite Systems (GNSSs) dominated navigation in air, sea, and land. Then, medium-range and long-range terrestrial navigation systems (TNSs) ceased to be developed. However, with the development of GNSS jamming and spoofing techniques, the TNSs are being re-developed, such as the Enhanced Loran. The Polish Ministry of Defense plans to develop and implement a medium-range backup navigation system for the Polish Navy which will operate in the Baltic coastal zone. This plan is a part of the global trend. This paper presents the concept of a reserve TNS (RNS) that is based on the signal Doppler frequency (SDF) location method. In 2016, the concept of the RNS, which is based on stationary radio beacons located on coastal lighthouses, has been presented. From the military viewpoint, the use of the mobile radio beacons, which may change their location, is more justified. Therefore, the paper presents an idea of using the mobile beacons for this purpose. In this paper, effectiveness of the mobile RNS is shown based on simulation studies.

14

Subsidence determination in the Central Valley, California

Romero M., Berber M. M.

Reports on Geodesy and Geoinformatics

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2018

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Vol. 106

35--42

EN

Twenty four hour GNSS (Global Navigation Satellite System) data acquired monthly for 5 years from 8 CORS (Continuously Operating Reference Station) stations in Central Valley, California are processed and vertical velocities of the points are determined. To process GNSS data, online GNSS data processing service APPS (Automatic Precise Positioning Service) is used. GNSS data downloaded from NGS (National Geodetic Survey) CORS are analyzed and subsidence at these points is portrayed with graphics. It is revealed that elevation changes range from 5 mm uplift in the north to 163 mm subsidence in the southern part of the valley.

15

Accuracy Evaluation of Real-Time GNSS Precision Positioning with RTX Trimble Technology

Ochałek A., Niewiem W., Puniach E., Ćwiąkała P.

Civil and Environmental Engineering Reports

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2018

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Vol. 28, no. 4

49--61

EN

In this paper, authors present results of accuracy verification of the Trimble RTX technology. The GNSS receiver Spectra Precision SP60 was used in Cyprus (Kato Paphos Archaeological Park). To evaluate the accuracy of the receiver, two measuring test networks (consisting of 30 and 55 control points) were established. All points were determined in four measuring cycles. Additionally, in order to make more advanced analysis of the data, the bases were also measured by using another GNSS receiver - Geomax-Zenith 25. The point positions, in this case, were conducted in the local coordinate system of Kato Paphos Archaeological Park by using RTK positioning technology. To make a comparison, it was necessary to transform the coordinates based on different groups of fitting points. Analysis allowed to conclude that the Spectra Precision SP60 receiver and the RTX Trimble technology guarantee repeatable results (on the level of 4 cm) of point positioning measurements.

PL

W artykule autorzy przedstawiają wyniki analizy dokładności technologii Trimble RTX. Odbiornik GNSS Spectra Precision SP60 wykorzystano podczas badań na Cyprze (Park Archeologiczny Kato Pafos). Aby ocenić dokładność odbiornika, ustalono dwie bazy testowe (składające się z 30 i 55 punktów kontrolnych). Wszystkie punkty zostały określone w czterech cyklach pomiarowych. Dodatkowo, w celu bardziej zaawansowanej analizy danych, pomiary zostały również wykonane przy użyciu innego odbiornika GNSS - Geomax-Zenith 25. Pozycjonowanie w tym przypadku, zostało przeprowadzone w lokalnym układzie współrzędnych parku archeologicznego Kato Pafos z wykorzystaniem technologii pozycjonowania RTK. W celu porównania wyników badań konieczne było przetransformowanie współrzędnych do jednego układu. Transformację wykonano na podstawie różnych grup punktów dostosowania. Analiza otrzymanych wyników pozwoliła stwierdzić, że odbiornik Spectra Precision SP60 i technologia RTX Trimble gwarantują porównywalne wyniki pozycjonowania (na poziomie 4 cm).

16

GPS/GNSS spoofing and the real-time single-antenna-based spoofing detection system

Ochin E.

Zeszyty Naukowe Akademii Morskiej w Szczecinie

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2017

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nr 52 (124)

145--153

EN

The idea of C/A codes GPS/GNSS Spoofing (Substitution), or the ability to mislead a satellite navigation receiver into establishing a position or time fix which is incorrect, has been gaining attention as spoofing has become more sophisticated. Various techniques have been proposed to detect if a receiver is being spoofed – with varying degrees of success and computational complexity. If the jammer signals are sufficiently plausible then the GNSS receiver may not realize it has been duped. There are various means of detecting spoofing activity and hence providing effective mitigation methods. In this paper, a novel signal processing method applicable to a single antenna handset receiver for spoofing detection has been described. Mathematical models and algorithms have been developed to solve the problems of satellite navigation safety. What has been considered in the paper is a spoofing detection algorithm based on the analysis of a civil satellite signal generated by mobile C/A GPS/GNSS single-antenna receivers. The work has also served to refine the civilian spoofing threat assessment by demonstrating the challenges involved in mounting a spoofing attack.

17

The concept of time in navigation

Weintrit A.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2017

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Vol. 11, no. 2

209--219

EN

The article discusses the concept of time in navigation, especially in marine navigation, as well as selected time measures, among others: Greenwich Mean Time (GMT), Universal Time Coordinated (UTC), International Atomic Time TAI (Temps Atomique International), GPST (Global Positioning System Time) eLoran Time and interrelation between these measures. Understanding how time is involved in navigation, and using it, is one of the navigator's most important duties. Nowadays we have satellite navigation to help us know where we are. These satellites contain several very precise and accurate clocks, because time and location are completely and totally inter-related in satellite navigation. There is growing interest internationally concerning the vulnerability Global Navigation Satellite Systems (GNSS) to natural and man-made interference, plus the jamming and spoofing of their transmissions. These vulnerabilities have led to a demand for sources of resilient PNT (Positioning, Navigation and Timing) [16], including a robust means of distributing precise time nationally and internationally.

18

Lotniczy skaning laserowy (LiDAR-ALS) jako źródło danych do obliczeń stateczności skarp na terenach zadrzewionych i zakrzewionych

Piechota A.

Przegląd Geologiczny

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2017

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Vol. 65, nr 10/2

811--816

EN

The paper discusses the problem of quick acquire height data for calculation of escarpment stability. In past the slope of profile was obtainedfrom classical land survey methods (like Total Station, GNSS, etc.), carto- metric measurement on maps or measurements based on a Digital Terrain Modelfrom aerial photography. Now we have a new method that is Airborne Laser Scanning (LiDAR-ALS). In 2011-2014 almost all country was measured in this method. The declared accuracy of height measurement on the durable surfaces is about 0.10-0.15 m. Author compared this method with classical method Global Navigation Satellite System - Real Time Network (GNSS-RTN) on two wooded and bushy areas. The comparison was based on the measurement characteristic points on the profiles and acquisition of height data from LiDAR-ALS data. Data in this method were obtained in two ways: from point cloud and from DTM createdfrom this point cloud. In the next step, height differences were calculated and these data were subjected to basic statistical calculations. The result of the study was a mean error of height data from LiDAR-ALS and conclusions about its usefulness in acquire height data for calculation of escarpment stability.

19

Estimation of UAV Position with Use of Smoothing Algorithms

Kaniewski P., Gil R., Konatowski S.

Metrology and Measurement Systems

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2017

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Vol. 24, nr 1

127--142

EN

The paper presents methods of on-line and off-line estimation of UAV position on the basis of measurements from its integrated navigation system. The navigation system installed on board UAV contains an INS and a GNSS receiver. The UAV position, as well as its velocity and orientation are estimated with the use of smoothing algorithms. For off-line estimation, a fixed-interval smoothing algorithm has been applied. On-line estimation has been accomplished with the use of a fixed-lag smoothing algorithm. The paper includes chosen results of simulations demonstrating improvements of accuracy of UAV position estimation with the use of smoothing algorithms in comparison with the use of a Kalman filter.

20

The test programme concerning aircraft positioning and traffic monitoring – part II

Jafernik H.

Zeszyty Naukowe. Transport / Politechnika Śląska

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2016

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z. 93

41--48

EN

This paper presents the results of studies on the determination of an aircraft’s trajectory and positioning accuracy. The PPP method was applied to determine the aircraft’s position in kinematic mode for code observations in the GPS system. Computations were executed in the “PPP_KINEMTIC” software, whose source code was written using the Scilab 5.3.2 platform. The PPP_KINEMTIC software allows for the latitude coordinate to be estimated with accuracy between 1 and 6 m, the longitude coordinate to be estimated with accuracy between 0.5 and 2.5 m, and the ellipsoidal height to be estimated with accuracy between 1 and 7 m. The average value of the MRSE term equals 5 m with a magnitude between 1 and 8.5 m. In the paper, general libraries of the PPP_KINEMTIC application were presented and the PPP method was characterized too.