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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.
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.
EN
The article discusses issues relating to the determination of a maneuvering area of an inland vessel. The author presents the methodology for defining the vessel's swept path width through simulation and field studies. The Global Positioning System has been characterized in view of possible use of GPS RTK to determine a safe maneuvering area of a ship sailing on inland waterway. The author also explains the procedure of measurements using GPS RTK and discusses problems that may be encountered during tests.
PL
W artykule omówiona została problematyka określania obszaru manewrowego statku śródlądowego. Przedstawiono metodologię określania szerokości pasa ruchu jednostki za pomocą badań symulacyjnych oraz rzeczywistych. Scharakteryzowano Globalny System Pozycjonowania i zaprezentowano możliwość wykorzystania GPS RTK do określania bezpiecznego obszaru manewrowego statku w żegludze śródlądowej. Omó-wiono procedurę wykonywania pomiarów za pomocą GPS RTK oraz problemy jakie można napotkać podczas przeprowadzania badań.
Logistyka
|
2015
|
nr 3
3101--3109, CD 1
PL
W artykule przedstawiono genezę powstania Systemu Globalnej Nawigacji – GPS oraz kolejne etapy jego rozwoju. Omówiono jego budowę i sposób funkcjonowania. Przedstawiono i omówiono segmenty składowe systemu. Opisano wykorzystywane urządzenia oraz metody określania pozycji. Wskazano na ograniczenia funkcjonalności systemu. Przedstawiono możliwe do osiągnięcia dokładności określania pozycji. Wskazano sposoby podwyższenia dokładności pomiarów poprzez zastosowanie technologii wymiany danych. Omówiono zarówno zakres, jak i sposoby wykorzystania Globalnego Systemu Pozycjonowania. Przedstawiono jego rolę w zastosowaniach o charakterze cywilnym w szeroko pojętej gospodarce. Wskazano inne systemy nawigacji satelitarne. Określono tendencje rozwoju technologii nawigacji satelitarnej.
EN
The article presents the history of the GPS System - GPS and the successive stages of its development. The design and operation are discussed. Author indicated and discussed about sub-segment of the system. Article describes the equipment used and the method of determining the position. Author pointed the limitations of the system functionality. Possibilities to achieve the accuracy of the positioning have been presented. Author identified ways to increase the accuracy of the measurements through the use of data exchange technology. Article deals with both the scope and methods of use of the Global Positioning System. The role in civilian applications in the wider economy have been presented. Other satellite navigation systems have been also . indicated. Trends in the development of satellite navigation technologies have been discussed in the paper.
EN
The article is devoted to the analysis of the possibilities of GPS-technology (Global Positioning System) in the tourism industry. The study is devoted to the identification and analysis of functionality of mobile computing devices equipped with GPS receiver in tourism industry, the methods and means of their implementation, building on this basis a mobile information technology for tourist support at all stages of his journey. To achieve the goal a number of mobile information systems using data GPS, methods and means of their implementation, a comparative analysis of current cartographic services that are used in the developing of mobile information technology applications for tourist are analyzed. The study outlines the place of GPS-technology in the "Mobile tourist information assistant" system, and the role of Google Maps services for information technology support and implementation of the main tourist features in mentioned mobile information system.
EN
Ionospheric time delay (VΔt) variability using Global Positioning System (GPS) data over Akure (7.15°N, 5.12°E), Nigeria, has been studied. The observed variability of VΔt in comparison to older results of vertical total electron content (TEC) across similar regions has shown equivalent signatures. Higher monthly mean values of VΔt (MVΔt) were observed during daytime as compared to nighttime (pre- and post- midnight) hours in all months. The highest MVΔt observed in September during daytime hours range between ~6 and ~21 ns (~1.80 and ~6.30 m) and at post-midnight, they are in the range of ~1 to ~6 ns (~0.3 to ~1.80 m). The possible mechanisms responsible for this variability were discussed. Seasonal VΔt were investigated as well.
PL
Przedstawiono przegląd wybranych komercyjnych systemów radiolokalizacyjnych pracujących w środowisku wewnątrzbudynkowym oraz zewnątrzbudynkowym. Opisano podstawy i zasady działania usług lokalizacyjnych oraz mechanizmy przetwarzania informacji w systemach GIS.
EN
In this paper we present a currently available radio location systems operating in both indoor and outdoor environments. We explain the fundamentals and operating principles of location-based services as well as information processing mechanisms in GIS systems.
EN
For the first time, a homogeneous coordinate solution in the IGS05 reference frame and the values of the zenith tropospheric refraction for the GPS weeks 935-1399 (from December 12, 1997 to November 4, 2006) were obtained at the GNSS Data Center Analysis of the Main Astronomical Observatory NAS of Ukraine. The obtained solution is devoid of effects, brought by changes in the methods of processing models, a priori data and software (absolute phase center model combinations of antenna-dome instead of relative models, model of ocean loading FES2004 instead of GOT00.2_PP, the elevations cut-off angle 3° instead of 10°, etc. were used). To estimate the quality of the solution, a comparison with the international combined solutions using the Helmert transformation was carried out. The RMS of direct station coordinate differences and correlation coefficients between the solutions estimated by the Main Astronomical Observatory, European GNSS Permanent Network and International GNSS Service are presented. The obtained results allow making the conclusion that the solution obtained at the GNSS Data Center Analysis of the Main Astronomical Observatory shows a good quality and agrees well with other solutions.
9
Content available remote Positional accuracy of GPS satellite almanac
EN
How to accelerate signal acquisition and shorten starting time are key problems in the Global Positioning System (GPS). GPS satellite almanac plays an important role in signal reception period. Almanac accuracy directly affects the speed of GPS signal acquisition, the start time of the receiver, and even the system performance to some extent. Combined with precise ephemeris products released by the International GNSS Service (IGS), the authors analyse GPS satellite almanac from the first day to the third day in the 1805th GPS week (from August 11 to 13, 2014 in the Gregorian calendar). The results show that mean of position errors in three-dimensional coordinate system varies from about 1 kilometer to 3 kilometers, which can satisfy the needs of common users.
10
Content available remote GNSS positioning algorithms using methods of reference point indicators
EN
The GNSS standard positioning solution determines the coordinates of the GNSS receiver and the receiver clock offset from measurements of at least four pseudoranges. For GNSS positioning, a direct solution was derived for five and ten observed satellites without linearisation of the observation equations and application of the least squares method. The article presents the basic principles of methods for solving the positioning problem, the formulas and their derivation. The numerical examples with simulated pseudorange data confirm the correct performance of the proposed algorithm. The presented algorithms should be further tested with real measurements in other domains of positioning and navigation as well.
PL
Omówiono strukturę organizacyjną i zasadę działania nawigacyjnego systemu GPS. Sformułowany dla tego systemu układ czterech równań nieliniowych rozwiązano analitycznie. Słuszność wyprowadzonych zależności matematycznych potwierdzono wynikami obliczeń symulacyjnych ilustrujących typowe zadania nawigacyjne.
EN
An organizational structure and principle of operation of the Global Positioning System are described. The set of four pseudo-ranging equations is formulated and solved analytically. For this purpose the method of quadrilateration has beeen used.The validity of all mathematical formulas derived in Section 3 has been confirmed by the results of numerous computer simulations concerning the typical navigation problems.
EN
Dual-frequency global navigation satellite systems (GNSS) observations provide most of the input data for development of global ionosphere map (GIM) of vertical total electron content (VTEC). The international GNSS service (IGS) develops different ionosphere products. The IGS tracking network stations are not homogeneously distributed around the world. The large gaps of this network in Middle East, e.g., Iran plateau, reduce the accuracy of the IGS GIMs over this region. Empirical ionosphere models, such as international reference ionosphere (IRI), also provide coarse forecasts of the VTEC values. This paper presents a new regional VTEC model based on the IRI 2007 and global positioning system (GPS) observations from Iranian Permanent GPS Network. The model consists of a given reference part from IRI model and an unknown correction term. Compactly supported base functions are more appropriate than spherical harmonics in regional ionosphere modeling. Therefore, an unknown correction term was expanded in terms of B-spline functions. The obtained results are validated through comparison with the observed VTEC derived from GPS observations.
13
Content available remote Onboard Wave Sensing with Velocity Information GPS
EN
Even though it is essential that the wave information promotes greater safety also efficiency to navigate and/or operate a ship not only ocean going but also docking/landing, it is very difficult to sense a wave information such as wave heights and periods or wave lengths in real time at the present time. On the other hand, the Velocity Information (VI) GPS is developed as the stand-alone 3D velocities measurement equipment of which accuracies are precise (less than 1 cm/s) and the coverage is all over the world. It is able to drive the wave information from the time history of not only wave amplitudes but also wave velocities. The algorithm to sense the wave information such as not only significant wave height but also plural wave heights and period intervals of encounter was presented by the authors in IAIN2009 and ANC2010. In this paper, the introduction and the performance of wave sensing with VI-GPS and some results of onboard experiments are described and discussed.
14
Content available remote Ground-based, Hyperbolic Radiolocation System with Spread Spectrum Signal - AEGIR
EN
At present the most popular radiolocation system in the world is Global Positioning System (GPS).As it is managed by the Department of Defence of the U.S.A., there is always the risk of the occasional inaccuracies or deliberate insertion of errors, therefore this system can not be used by secret services or ar-mies of countries other than the U.S.A. This situation has engender a need for development of an autono-mous, ground-based radiolocation system, based on the hyperbolic system with spread spectrum signals. This article describes the construction and operation of such a system technology demonstrator which was devel-oped at the Technical University of Gdansk. It was named AEGIR (god of the ocean in Norse mythology). This paper presents preliminary results and analysis of its effectiveness.
PL
W artykule przedstawiono zagadnienia związane przeliczaniem i transformacją współ- rzędnych w odwzorowaniach kartograficznych. Zamieszczono gotowe wzory i algorytmy służące do realizacji zadań związanych z przeliczaniem i transformacją współrzędnych. Objaśniono również podstawowe pojęcia używane w geodezji i kartografii.
EN
In the paper the issues concerning conversion and transformation of coordinates in map projections were presented. The formulae and the algorithms for carrying out the tasks connected with the conversion and the transformation of coordinates were quoted. The basic terms used in geodesy and cartography were also explained.
PL
Pomimo, że globalny system pozycjonowania GPS ma szerokie zastosowanie w nawigacji pojazdów lądowych to nie jest on w stanie zapewnić ciągłości wyznaczania rozwiązania nawigacyjnego w sytuacjach zakłócenia lub zaniku sygnału satelitarnego występującego w silnie zalesionych obszarach, zabudowie miejskiej, mostach kratownicowych, czy też tunelach. Sposobem na rozwiązanie powyższego problemu jest budowa zintegrowanych systemów nawigacyjnych. Na przykładzie czterech schematów strategii przedstawiono metody integracji systemów nawigacyjnych. Omówione zostały również wady, zalety i koszty integracji. Głównym celem publikacji jest kompleksowy przegląd i synteza literatury z zakresu budowy zintegrowanych systemów nawigacyjnych.
EN
Although the Global Positioning System has been widely used in the navigation of land vehicle, that system is still unable to provide continuous and reliable navigation solutions in the occurrence of satellite signal fading or blockage from obstacles such as trees, buildings, overpasses and tunnels. The way to solve the issue above is building integrated navigation systems. Basing on the four schemes of strategy the methods of integration in navigation systems have been introduced. Advantages, disadvantages and costs of integration were presented in the paper. The main aim of the publication is complex review and synthesis of literature within the scope of integrated navigation systems.
PL
Przedstawiamy podstawowe metody pomiaru prędkości oraz możliwość wykorzystania w tym celu systemu GPS, a także sposoby wykorzystania analizy danych uzyskanych z pomiarów prędkości.
EN
The article presents the basic method of measuring speed. Indicated the possibility of using GPS to measure speed in traffic. Presents the results of velocity measurements using the GPS system in Radom. The article also discusses possible ways to use the analysis of data obtained from velocity measurements.
PL
Przedstawiamy wyniki badań dotyczące dokładności pozycjonowania statku powietrznego z wykorzystaniem systemu GPS oraz EGNOS. Loty eksperymentalne wykonano w 2010 roku, w południowo - wschodniej części Polski - w Dęblinie oraz Chełmie.
EN
The paper presents results of the research concerning determination of aircraft positioning accuracy with the use of GPS and EGNOS. Experimental flights were carried out in 2010, in south-eastern part of Poland, in Dęblin and Chełm. Precise trajectory of the aircraft was determined with the use of dual frequency geodetic Topcon receivers with centimeter accuracy. The reference position was compared with data logged by two navigation receivers - Thales MobileMapper working in autonomous and EGNOS mode.
EN
At present speed ranges for Levels of Service (LOS) categories are not well defined for highly heterogeneous traffic flow on urban streets in Indian context. In this regard a study was carried out in the city of Mumbai in India. The objective of this research work is to define free-flow speed ranges of urban street classes and speed ranges of LOS categories. In this regard speed data were collected using GPS palmtop and Fuzzy C-Means (FCM) clustering is used to define the speed ranges. It is found from this study that speed-ranges for LOS categories in Indian context are lower than that mentioned in Highway Capacity Manual.
20
Content available remote Ship Manoeuvring Performance Experiments Using a Free Running Model Ship
EN
In this paper, a 3m-class free running model ship will be introduced with its manoeuvring per-formance experiments. The results of turning circle test and zig-zag test will be explained. The developed system are equipped with GPS, main control computer, wireless LAN, IMU (Inertial Measurement Unit), self-propulsion propeller and driving rudder. Its motion can be controlled by RC (Radio Control) and wireless LAN from land based center. Automatic navigation is also available by pre-programmed algorithm. The trajectory of navigation can be stored by GPS and it provides us with important date for ship’s motion control experiments. The results of manoeuvring performance experiment have shown that the developed free run-ning model ship can be used to verify the test of turning circle and zig-zag. For next step, other experimental researches such as ship collision avoidance system and automatic berthing can be considered in the future.
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