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1

The Use of Artificial Intelligence in Enhancing Navigation Safety in Case of GNSS Signal Fading or Interference

Chrzan Marcin

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

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2025

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Vol. 19 No. 2

589--597

EN

Global Navigation Satellite Systems (GNSS) play a key role in modern navigation and transportation service delivery. Today it is difficult to imagine the daily operation of land, sea or air transportation without the positioning and timing provided by satellite systems [6, 8, 11]. In civil aviation, GNSS provides precision landing approaches and support for safety systems, in maritime navigation it enables open sea course determination and maneuvering, and on land it directs vehicle navigation and synchronization of telecommunications networks. Many of these applications are so-called PNT (Positioning, Navigation and Timing) systems, where uninterrupted and accurate position and timing information is critical to safe operations [8]. Unfortunately, satellite systems have recently become the target of hacking attacks. This paper will present AI methods for detecting GNSS anomalies, the role of inertial systems as an independent navigation source, and position correction techniques (e.g., using Kalman filters) supported by intelligent algorithms. An overview of current research and experiments in this field will also be presented, as well as conclusions on the effectiveness and development prospects of the technologies discussed.

2

AIS R-mode trilateration for GPS positioning and timing insurance

Shyshkin O. V., Konovets V. I., Koshevyy V. M.

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

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2024

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Vol. 18 No. 2

369--374

EN

Satellite navigation is the backbone of maritime navigation today. However, the technical vulnerability of on-board Global Navigation Satellite System (GNSS) receivers the satellite system greatly destabilizes maritime security due to the loss of ship’s position and accurate time. This article devoted to study an alternative method for obtaining coordinates and accurate time based on the use of automatic identification system (AIS) radio channels, so-called range mode (R-Mode). We use other AIS ship stations with reliable position data as reference stations and determine time of arrival for received AIS transmissions. To improve the accuracy of measuring signal arrival instance in the time difference of arrival (TDOA), that we utilize for trilateration, it is proposed signal oversampling and applying the fast Fourier transform (FFT) to the product of quadrature components of the baseband Gaussian minimum shift keying (GMSK) signal in the window of AIS time slot. To take into account the movement of other ships, appropriate coordinate corrections are foreseen, which can be calculated by dead reckoning or by the inertial navigation system of our ship. The proposed method is fully compatible with the existing AIS signals and may be employed in critical situations of locally limited (jamming, spoofing) GNSS abilities. It can be implemented as a separate unit, working for receiving in parallel with the mandatory AIS transponder.

3

INS/GPS KF integration performance improvement based on accurate inertial sensors sochastic error modelling

Shahrawy Ahmed, Radi Ahmed, Zahran Shady, Anis Wagdy

Przegląd Elektrotechniczny

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2024

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R. 100, nr 6

219--226

EN

Inertial Navigation Systems (INS) provides precise data for short time-period, but their accuracy diminishes over time, especially with low cost sensors. To maintain acceptable accuracy, sensor error components must be accurately calibrated/modelled. Different methods have been used to characterize the inertial sensors stochastic errors, including the Autocorrelation function (ACF), Allan variance (AV) and the Generalized Method of Wavelet Moments (GMWM). This paper focuses on the analysis of Micro-Electromechanical Systems (MEMS)-based inertial sensor errors under various conditions. The inertial sensor stochastic error processes are estimated using both the AV and the GMWM techniques. Based on the comparison between both stochastic analysis tools, the GMWM was selected and a GMWM-based model selection criteria is utilized to rank candidate error models. An extended 39-states integrated GNSS/INS navigation algorithm (based on the chosen error model) is proposed and compared with a standard 15- states integrated GNSS/INS navigation algorithm (based on 1st Gauss-Markov process for modelling the stochastic errors). The study analyses various stochastic error models using real data of Inertial Navigation System (INS) and Global Positioning System (GPS) with intended GPS signal outage periods. Results reveal enhanced position accuracy with the proposed algorithm and superior performance with GMWM-based error model over standard ACF-based one.

PL

Inercyjne systemy nawigacji (INS) dostarczają dokładnych danych przez krótki okres czasu, ale ich dokładność maleje z czasem, szczególnie w przypadku tanich czujników. Aby zachować akceptowalną dokładność, składowe błędu czujnika muszą być dokładnie skalibrowane/modelowane. Do charakteryzowania błędów stochastycznych czujników inercyjnych zastosowano różne metody, w tym funkcję autokorelacji (ACF), wariancję Allana (AV) i uogólnioną metodę momentów falkowych (GMWM). W artykule skupiono się na analizie błędów czujników inercyjnych opartych na systemach mikroelektromechanicznych (MEMS) w różnych warunkach. Procesy błędów stochastycznych czujnika inercyjnego są szacowane przy użyciu technik AV i GMWM. Na podstawie porównania obu narzędzi analizy stochastycznej wybrano GMWM, a kryteria wyboru modelu oparte na GMWM zastosowano do uszeregowania modeli potencjalnych błędów. Zaproponowano rozszerzony, 39-stanowy zintegrowany algorytm nawigacji GNSS/INS (oparty na wybranym modelu błędów) i porównano go ze standardowym 15-stanowym zintegrowanym algorytmem nawigacji GNSS/INS (opartym na pierwszym procesie Gaussa-Markowa do modelowania błędów stochastycznych). W pracy przeanalizowano różne modele błędów stochastycznych wykorzystując rzeczywiste dane z systemu nawigacji inercyjnej (INS) i globalnego systemu pozycjonowania (GPS) z przewidywanymi okresami zaniku sygnału GPS. Wyniki ujawniają zwiększoną dokładność pozycjonowania dzięki proponowanemu algorytmowi i lepszą wydajność dzięki modelowi błędów opartemu na GMWM w porównaniu ze standardowym modelem opartym na ACF.

4

Converting Coordinates Between the Local Geodetic Reference and the Global Geodetic Reference for Selective Sites in Babil Province

Al-Saedi Ali Salah J., Shnewer Fadhil M., Falih Khaldoon T.

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 4

38--44

EN

A geodetic transformation is a mathematical operation that takes coordinates of a point in one coordinate system and returns the same coordinates in another coordinate system. This study aimed to show the compatibility between global positioning system coordinates and the local maps in Iraq; this compatibility will be made for locations in the Babil province. In the study area, fifteen control points have been chosen. GPS measures geographic and projected coordinates depending on the Universal Transverse Mercator projection and the World Geodetic System 1984 datum. In Iraq, the measured geographic coordinates are converted to projected coordinates using a geographic information system based on Clarke 1880 ellipsoid. To facilitate the conversion of the coordinates, both formulas and parameters are provided for any point in the study area between the two systems using a GPS receiver and the ArcGIS software. The present study shows that the differences in easting coordinates are about -287.630 m, while the differences in northing coordinates reach 278.525 m. It was concluded that the various datums might play a significant role in producing maps and updating those maps for engineering works.

5

Trojan spoofing: A threat to critical infrastructure

Westbrook Tegg

Security and Defence Quarterly

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2023

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Vol. 42, No. 2

1--15

EN

This article explores the phenomenon of location spoofing—where the spoofer is able to “teleport” systems in and out of defined locations, either for the purpose of infiltration into no-go zones or for the “teleportation” out of real, defined zones in the physical world. The research relied on a qualitative methodology, utilising academic research findings, media reports, hacker demonstrations, and secondary data from these sources, to situate the spoofing threat in the context of international security. This conceptual, argumentative essay finds that signal spoofing, the methods of which can be followed via online scripts, allows users the ability to overcome geographically defined territorial restrictions. This, as this article finds, allows violent actors to weaponise systems, such as unmanned aerial systems, potentially leading to the escalation of political tensions in extreme but unfortunately ever-frequent episodes. The article concludes that, while Trojan spoofing (in particular) poses a real and an existential threat to international security, it is only a sum-of-all parts in considering other threats to critical functions in society. If geofences are used as a single point of security to protect assets against hostile actors, managers need to be aware of the vulnerability of intrusion and the resulting geopolitical consequences.

6

Investigate Bending Effect of Wearable GPS Patch Antenna with Denim and Polyester Fabric Substrate

Radhakrishna Kavinesh S., Shakhirul M. S., Lee Y. S., Khairina K. N., Syafiqah A. R. A.

International Journal of Electronics and Telecommunications

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2023

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Vol. 69, No. 2

225--231

EN

In high technologies today, wearable devices have become popular. Wearable technology is a body sensing system that supports application of health observance and tracking through a wearable Global Positioning System (GPS). The design of the patch antennas is highly significant for the brilliance of the wearable patch antennas. This paper focuses on analyzing the bending effect on return loss and frequency between three types of GPS patch antenna. Types of GPS patch antennas that have been designed in this project are with different substrates and different designs. The wearable patch antenna has been designed and analyse using CST software. As a result, able to analysis the reflection coefficient (S11), radiation patterns, and analytical approach for patch antenna bending effect were obtained.

7

Rozwój koncepcji bezzałogowego holownika szybowców i dronów towarowych o napędzie elektrycznym

Jafernik Henryk, Muszyński Tomasz, Puzio Łukasz

Przegląd Komunikacyjny

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2022

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R. 77, nr 2/3

10--15

PL

W artykule przedstawiono kilka wybranych propozycji zastosowań BSP rozwijanych w Polsce. Przedstawiono opis projektu bezzałogowego holownika, nowego rozwiązania technicznego, zgłoszonego do urzędu patentowego w grudniu 2017 roku i rozwijanego do chwili obecnej. Proponowany system holu składa się z uniwersalnej stacji naziemnej kontroli lotów bezzałogowców, BSP-holownika i dodatkowego systemu sterowania umieszczonego na obiekcie holowanym. Proponowane rozwiązanie ma na celu zmniejszenie kosztów eksploatacji oraz poprawę osiągów statków powietrznych o napędzie elektrycznym.

EN

The article presents a few selected ideas for AUV usage which are being developed in Poland as well as the description of a project of an unmanned tug, a new technological solution which was submitted to the Patent Office in December 2017 and which has been being developed since then. The proposed towing system consists of a universal ground-based air traffic control station for unmanned flights, an AUV-tug and an additional control system placed on the towed object. The proposed solution aims at maintenance costs reduction and increase of performance of aircrafts with electric drive.

8

Experimental studies on the relationship between HDOP and position error in the GPS system

Specht Mariusz

Metrology and Measurement Systems

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2022

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Vol. 29, nr 1

17--36

EN

2D position error in the Global Positioning System GPS depends on the horizontal dilution of precision (HDOP) and User Equivalent Range Error UERE. The non-dimensional HDOP coeffcient, determining the influence of satellite distribution on the positioning accuracy, can be calculated exactly for a given moment in time. However, the UERE value is a magnitude variable in time, especially due to errors in radio propagation (ionosphere and troposphere effects) and it cannot be precisely predicted. The variability of the UERE causes the actual measurements (despite an exact theoretical mathematical correlation between the HDOP value and the position error) to indicate that position errors differ for the same HDOP value. The aim of this article is to determine the relation between the GPS position error and the HDOP value. It is possible only statistically, based on an analysis of an exceptionally large measurement sample. To this end, measurement results of a 10-day GPS measurement campaign (900,000 fixes) have been used. For HDOP values (in the range of 0.6-1.8), position errors were recorded and analysed to determine the statistical distribution of GPS position errors corresponding to various HDOP values. The experimental study and statistical analyses showed that the most common HDOP values in the GPS system are magnitudes of: 0.7 (𝑝 = 0.353) and 0.8 (𝑝 = 0.432). Only 2.77% of fixes indicated an HDOP value larger than 1. Moreover, 95% of measurements featured a geometric coeffcient of 0.973 - this is why it can be assumed that in optimal conditions (without local terrain obstacles), the GPS system is capable of providing values of HDOP ≤ 1, with a probability greater than 95% (2𝜎). Obtaining a low HDOP value, which results in a low GPS position error value, calls for providing a high mean number of satellites (12 or more) and low variability in their numer.

9

An Interactive Graphical User Interface Module for Soldier Health and Position Tracking System

Swedan Wesam F., Al Issa Huthifa A., Aloqoul Ayat, Alkofahi Hadeel, Obeidat Rahaf

International Journal of Electronics and Telecommunications

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2022

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Vol. 68. No. 3

571--571

EN

Soldiers are the backbone of any armed force. They usually lose their lives due to the lack of medical assistance in emergency situations. Furthermore, army bases face problems due to the inability to track soldiers’ locations in the field. Hence, this paper proposes an interactive graphical user interface module (IGUIM) for soldiers’ bioinformatics acquisition and emergency reaction during combat, a global positioning system (GPS) is used to track soldiers’ locations through a device carried by the soldier. Soldiers’ bioinformatics are gathered using health monitoring biosensors, bidirectional communication between the soldiers and the army base is established via a global system for mobile (GSM). The proposed interactive module aims to enumerate the soldiers on the battlefield within a database that easily facilitates health monitoring, position tracking and bidirectional communication with each soldier through their identification number. The proposed IGUIM will increase the rate of soldiers’ survival in emergencies, which contributes to preserving the human resources of the army during combat.

10

A review of the importance of synchrophasor technology, smart grid, and applications

Baba Maveeya, Nor Nursyarizal B. M., Sheikh Aman, Nowakowski Grzegorz, Masood Faisal, Rehman Masood, Irfan Muhammad, Arefin Ahmed Amirul, Kumar Rahul, Baba A. Momin

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 6

art. no. e143826

EN

The electrical network is a man-made complex network that makes it difficult to monitor and control the power system with traditional monitoring devices. Traditional devices have some limitations in real-time synchronization monitoring which leads to unwanted behavior and causes new challenges in the operation and control of the power systems. A Phasor measurement unit (PMU) is an advanced metering device that provides an accurate real-time and synchronized measurement of the voltage and current waveforms of the buses in which the PMU devices are directly connected in the grid station. The device is connected to the busbars of the power grid in the electrical distribution and transmission systems and provides time-synchronized measurement with the help of the Global Positioning System (GPS). However, the implementation and maintenance cost of the device is not bearable for the electrical utilities. Therefore, in recent work, many optimization approaches have been developed to overcome optimal placement of PMU problems to reduce the overall cost by providing complete electrical network observability with a minimal number of PMUs. This research paper reviews the importance of PMU for the modern electrical power system, the architecture of PMU, the differences between PMU, micro-PMU, SCADA, and smart grid (SG) relation with PMU, the sinusoidal waveform, and its phasor representation, and finally a list of PMU applications. The applications of PMU are widely involved in the operation of power systems ranging from power system control and monitor, distribution grid control, load shedding control and analyses, and state estimation which shows the importance of PMU for the modern world.

11

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.

12

GPS Synchronization of audio watermarks in the Maritime Automatically Identified Radiotelephony

Shyshkin O. V., Koshevyy V. M., Ryaboshapka I. V.

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

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2021

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Vol. 15 No. 2

307--312

EN

Audio watermarking (AW) technology in cooperation with GPS synchronization of watermarked frames is proposed for application in the maritime VHF communication for automatic identification of radiotelephone messages. Automatic identification ensures efficient messaging from the very beginning of a radio transmission, while eliminating the human factor inherent in voice identification. AW refers to inaudible embedding of additional data just into the post microphone signal, using standard marine installations without any additional radio channel resources. The designed algorithm is based on data embedding in the Fast Fourier Transform domain with the rate of 32 bit/s. The experimental prototype of the device is designed on the base of micro-controller development kit 32F429IDISCOVERY and GPS module NEO-6M-0-001. Designed system, applied for automatic ship’s identification, provides the full compatibility with the existing radio installation, and does not require replacement of standard VHF transceivers and operational procedures. Besides automatic identification the system may be used in the special applications, for example, by the threat of terrorist attack; generally contributes to navigation safety and information security.

13

An optimal innovation based adaptive estimation Kalman filter for accurate positioning in a vehicular ad-hoc network

Sumithra S., Vadivel R.

International Journal of Applied Mathematics and Computer Science

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2021

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Vol. 31, no. 1

45--57

EN

The vehicular ad-hoc network (VANET) is subject to various attacks because of its dynamic nature and ephemeral character. In VANET, vehicles communicate with each other for safety awareness. The positioning of an unknown vehicle is one of the critical factors to determine the vehicle’s trustworthiness. Although some positioning techniques have achieved a high accuracy level in VANET, they suffer from dynamic noise in real-world environments. This drawback leads to inaccuracy and unreliability during vehicle positioning. In this paper, an optimal innovation based adaptive estimation Kalman filter (OIAE-KF) is proposed. This algorithm offers an alternative solution for the basic Kalman filter and the innovation based adaptive estimation Kalman filter (IAE-KF). The proposed algorithm makes use of fusion of the global navigation satellite system (GNSS) and the inertial measurement unit (IMU) to improve its performance. The OIAE-KF works based on the innovation sequence and involves three steps such as establishing the innovation sequence, applying the innovation property, checking the optimality of the Kalman filter and, finally, estimating process noise (Q) and measurement noise (R). An optimal swapping method is introduced for optimality check. The efficiency of the proposed OIAE-KF method is proved by comparing the predictions of the existing methods such as the IAE-KF. The results show that the OIAE-KF performs better than the existing techniques. It improves the accuracy and consistency in VANET positioning.

14

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.

15

Reconstruction of geomagnetic event as observed in Northern Adriatic region and Its correlation with GPS single-frequency positioning deviations

Brčić D., Ćelić J., Valčić S.

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

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2020

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Vol. 14, no. 2

349--357

EN

Space weather effects are generally recognized as causes of degradation of satellite positioning, navigation and timing (PNT) services. We analyze GPS position estimation error during a geomagnetic storm, focusing on manifestations of geomagnetic processes. The position estimation error was analyzed in terms of GPS coordinates’ deviations (latitude, longitude and height) from their reference values. The storm’s impact was studied in the Northern Adriatic region where GPS observables from two Global Navigation Satellite System (GNSS) reference stations were analysed. Geomagnetic indices were elaborated, comprising readings from interplanetary, magnetospheric and geomagnetic observatories. Total Electron Content (TEC) on both stations was computed using dual frequency GPS pseudorange observables. The experiment was to reconstruct the movement of geomagnetic disturbances entering the geospace, reaching the earth’s surface. The aim was to correlate possible space weather manifestation on satellite positioning performance in terms of positioning error. Regularities in changes in positioning deviations were identified with relation to influential indices. The research offered a possibility of experimental positioning deviations assessment as well as forecasting. Evaluation of generated rudimentary Classification and Regression Trees (CART) models showed that the risk of satellite positioning errors could be assessed and predicted considering absolutes, as well as changes in values of geomagnetic indices. During the research process, several activities emerged as preferable continuation of the work, with the aim of further development of predictive models and the complement of space weather scenarios and their consequences on navigational systems. Along with summarized results, they are outlined in the conclusion section.

16

Analysis of tropospheric contribution to GPS positioning error during tropospheric cyclone Marcus in 2018

Sikirica N., Horvat M., Špoljar D., Rumora I.

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

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2020

|

Vol. 14, no. 2

343--348

EN

GNSS positioning performance assessment is essential for sustainable development of a growing number of GNSS-based technology and socio-economic applications. Case-studies of GNSS positioning performance in critical environments and applications scenarios reveals vulnerabilities of the GNSS Positioning, Navigation, and Timing (PNT) services, and suggest mitigation techniques and GNSS application risk containment. Here we address the case of GPS positioning performance during a devastating tropical cyclone Marcus that hit the greater area of the city of Darwin, Australia in 2018. We identified specific statistical properties of time series of tropospheric contribution to GPS northing, easting, and vertical positioning error that may contribute to understanding of tropospheric effects on GPS positioning performance during a massive weather deterioration in maritime and coastal areas, and analysed their adversarial effects on GNSS-based maritime applications.

17

An influence of the covariance between single orbit parameters on the accuracy of observations of the pseudo-ranges and phase differences

Skeivalas Jonas, Paršeliūnas Eimuntas, Putrimas Raimundas, Šlikas Dominykas

Metrology and Measurement Systems

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2020

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Vol. 27, nr 1

131--140

EN

The possibilities to improve values of the satellite orbit elements by employing the pseudo-ranges and differences of carrier phase frequencies measured at many reference GPS stations are analysed. An improvement of orbit ephemeris is achieved by solving an equation system of corrections of the pseudo-ranges and phase differences with the least-squares method. Also, equations of space coordinates of satellite orbit points expressed by ephemeris at fixed moments are used. The relation between the accuracy of the pseudo-ranges and phase differences and the accuracy of the satellite ephemeris is analysed. Formulae for estimation of the influence of the ephemeris on the measured pseudo-ranges and phase differences and for prediction of the accuracy of the pseudo-ranges and phase differences were obtained. An influence of the covariance between single orbit parameters on the accuracy of the pseudo-ranges and phase differences is detected.

18

Map Matching Algorithm Based on Dynamic Programming Approach

Yumaganov Alexander, Agafonov Anton, Myasnikov Vladislav

Annals of Computer Science and Information Systems

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2020

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Vol. 21

563--566

EN

GPS sensors embedded in almost all mobile devices and vehicles generate a large amount of data that can be used in both practical applications and transportation research. Despite the high accuracy of location measurements in 3-5 meters on average, this data can not be used for practical use without preprocessing. The preprocessing step that is needed to identify the correct path as a sequence of road segments by a series of location measurements and road network data is called map matching. In this paper, we consider the offline map matching problem in which the whole trajectory is processed after it has been collected. We propose a map matching algorithm based on a dynamic programming approach. The experimental studies on the dataset collected in Samara, Russia, showed that the proposed algorithm outperforms other comparable algorithms in terms of accuracy.

19

Use of a least squares with conditional equations method in positioning a tramway track in the Gdansk agglomeration

Czaplewski K., Specht C., Dąbrowski P., Specht M., Wiśniewski Z., Koc W., Wilk A., Karwowski K., Chrostowski P., Szmagliński J.

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

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2019

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Vol. 13. no. 4

895--900

EN

Satellite measurement techniques have been used for many years in different types of human activity, including work related to staking out and making use of rail infrastructure. First and foremost, satellite techniques are applied to determine the tramway track course and to analyse the changes of its position during its operation. This paper proposes using the least squares with conditional equations method, known in geodesy (LSce). When applied, this method will allow for improvement of the final determination accuracy. This paper presents a simplified solution to the LSce alignment problem. The simplification involves replacement of the parameter binding equations with equivalent observational equations with properly selected weights. The results obtained with such a solution were demonstrated with a randomly selected section of a tramway track in Gdańsk. The article presents the theoretical foundations of the test method, the experiment organisation and the results obtained with MathCad Prime 3.0 software. It also presents the outcome of a study associated with the execution of the project No POIR.04.01.01-00-0017/17 entitled “Developing an innovative method of precision determination of a rail vehicle trajectory” executed by a consortium of the Gdańsk University of Technology and Gdynia Maritime University.

20

Polish DGPS System: 1995-2018 – studies of reference station operating zones

Specht C., Specht M., Dąbrowski P. S.

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

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2019

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Vol. 13, no. 3

581--586

EN

The operating zone of a radio navigation system is one of its main operating features. It determines the size of a water body in which the system can be used, while guaranteeing vessels’ navigation safety. The DGPS system in the LF/MF range is now the basic positioning system in coastal waters around the world, which guarantees not only metre positioning accuracy, but it is also the only one to provide navigators with signals on positioning reliability. This paper describes and summarises over twenty years of studies dealing with the operating zone of the Polish DGPS reference station network. This paper is the fifth in a series of publications whose aim was to present in detail the process of installation, testing and long-term evaluation of the navigational parameters of the Polish DGPS system, launched in 1995. This paper includes the theoretical foundations of determination of the Dziwnów and Rozewie DGPS reference station operating zones in the years 1995-2018. Moreover, it presents the measurement results for the signal levels and the results of their analyses, which determine the station operating zones.