Digital information system for inland water transport vessels based on AIS

The most important role in ensuring navigation safety on inland waterways is played by the timely provision of navigators with timely and reliable navigational, meteorological and track information, as well as safety information. To solve this problem, the complexes of automatic identification stations’ coastal and ship networks deployed currently can be used. This communication channel (with free traffic for inland waterway transport) is currently used extremely ineffectively due to a small number of serviced vessels. The article substantiates the structure of a digital information system based on deployed networks of automatic identification stations for inland navigation vessels and its functional purpose. The issues of algorithmic and software support development for the process of preparation, transmission, reception and processing of transmitted information are considered. The structure of the database and algorithms for the formalized information packets’ formation in the direction of bank-to-ship are proposed. The formats of address and broadcast messages are presented. A variant of transmitting differential corrections to ships from control-correcting stations via networks of automatic identification stations without using the currently used radio channel is considered. The options for the dialog boxes of the digital information system for the dispatcher and the navigator are given.

GNSS-technologies in testing automotive ADAS-system

In this article modern technologies are reviewed, they are used in testing ADAS systems, the principle of which is based on the use of global navigation systems (GNSS) and the using of differential corrections. The specialists of the Nizhny Novgorod State Technical University n. a. R. E. Alekseev have developed a schematic diagram in which Racelogic measuring equipment is used. The performance of the testing system was verified during tests of a bus based on a light commercial vehicle GAZelle Next while simulating the operation of the adaptive cruise control function. In the conclusion, graphs of a number of measured parameters are presented, the nature of the change in time confirms the correct functioning of the measuring equipment. Keywords: GNSS, Glonass, GPS, ADAS, testing, radiocommunication, RTK

POSSIBILITIES OF EXPANDING THE COVERAGE AREA OF LOCAL FUNCTIONAL ADDITIONS WHILE PROVIDING HIGH-PRECISION CORRECTIONS OF SATELLITE RADIO NAVIGATION SYSTEM ERRORS

Анализируются методы высокоточной коррекции погрешностей спутниковой радионавигационной системы (СРНС). Предлагается рассмотреть усовершенствованную версию, основанную на определении дифференциальных поправок (ДП) сети децентрализованных станций, обеспечивающих расширение зоны действия локальных функциональных дополнений. С этой целью вычисляются поправки в реальном масштабе времени, практически лишенные ионосферной и тропосферной составляющих. Такой метод позволяет устранить некоторые флуктационные составляющие оценок псевдо- дальностей (ПД) и, таким образом, значительно (до нескольких тысяч километров) увеличить зону аппроксимации, обеспечив высокую точность поправок. The methods of high-precision error correction of the satellite radio navigation system are analyzed. It is proposed to consider an improved version of correction based on the definition of differential corrections of a chain of decentralized stations. For this purpose, realtime corrections, practically deprived of ionospheric and tropospheric components, are calculated.

Accuracy Analysis of Aircraft Position at Departure Phase Using DGPS Method

The aim of this paper is to present the problem of implementation of the Differential Global Positioning System (DGPS) technique in positioning of the aircraft in air navigation. The aircraft coordinates were obtained based on Global Positioning System (GPS) code observations for DGPS method. The DGPS differential corrections were transmitted from reference station REF1 to airborne receiver using Ultra High Frequency (UHF) radio modem. The airborne Thales Mobile Mapper receiver was mounted in the cabin in Cessna 172 aircraft. The research test was conducted around the military aerodrome EPDE in Dęblin in Poland. In paper, the accuracy of aircraft positioning using DGPS technique is better than 1.5 m in geocentric XYZ frame and ellipsoidal BLh frame, respectively. In addition, the obtained accuracy of aircraft positioning is in agreement with International Civil Aviation Organization (ICAO) Required Navigation Performance (RNP) technical standards for departure phase of aircraft. The presented research method can be utilised in Ground-Based Augmentation System (GBAS) in air transport. In paper, also the accuracy results of DGPS method from flight test in Chełm are presented. The mean values of accuracy amount to ±1÷2 m for horizontal plane and ±4÷5 m for vertical plane.

BDS Satellite-Based Augmentation Service Correction Parameters and Performance Assessment

BDS (Beidou Navigation Satellite System) integrates the legacy PNT (Positioning, Navigation, Timing) service and the authorized SBAS (Satellite-Based Augmentation Services) service. To support the requirement of decimeter-level positioning, four types of differential corrections are developed in the BDS SBAS, including the State Space Representation (SSR)-based satellite orbit/clock corrections, the Observation Space Representation (OSR)-based ionospheric grid corrections, and the partition comprehensive corrections. In this study, we summarize the features of these differential corrections, including their definition and usages. The function model of precise point positioning (PPP) for dual- and single-frequency users using the four types of BDS SBAS corrections are proposed. Datasets are collected from 34 stations over one month in 2019, and PPP is performed for all the datasets. Results show that the root mean square (RMS) of the positioning errors for static/kinematic dual-frequency (DF) PPP are of 12 cm/16 cm in horizontal and 18 cm/20 cm in vertical component, while for single-frequency (SF) PPP are of 14 cm/32 cm and 22 cm/40 cm, respectively. With regard to the convergence performance, the horizontal and vertical positioning errors of kinematic DF-PPP can converge to 0.5 m in less than 15 min and 20 min, respectively. As for the kinematic SF-PPP, it could converge to 0.8 m in horizontal and 1.0 m in vertical within 30 min, where the ionosphere-constrained PPP performs better than the UofC PPP approach, owing to the contribution of the ionospheric grid corrections.

Improvement of Single-Frequency GPS Positioning Performance Based on EGNOS Corrections in Algeria

The main objective of the European Geostationary Navigation Overlay System (EGNOS) is to improve the positioning accuracy by correcting several error sources affecting the Global Positioning System (GPS) and to provide integrity information to GPS signals for users in real time. This research presents analysis used to investigate improvement in the performance of single-frequency GPS positioning using EGNOS corrections in Algeria. In this study, we performed position measurements with two calculation approaches, the first based on GPS single-point positioning and the second using EGNOS differential corrections. Positioning accuracy was determined by comparison with the known precise coordinates of the sites; and then the improved ionospheric correction using EGNOS was investigated. The results revealed that GPS + EGNOS performance was significantly improved compared with GPS alone, when measurements of horizontal and vertical accuracy were taken into account, and that the EGNOS corrections improved east and north components slightly, and the up component significantly.

Peculiarities Regarding Satellite Navigation on the Territory of Romania

This paper describes the particularities of satellite navigation on the territory of Romania in search of solutions to improve the accuracy of these systems. The performance of a Global Navigation Satellite System (GNSS) is influenced by many factors, including distortion of the signal, the influence of the ionosphere and the troposphere, multipath propagation. Some of these factors depend on the geographical position and the environment in which the navigation system is used. Moreover, Romania is located at the border of coverage of two Satellite Based Augmentation Systems (SBAS) – European Geostationary Navigation Overlay Service (EGNOS) and System for Differential Corrections and Monitoring (SDCM) which leads to some peculiarities regarding satellite navigation.

Method of Dynamic Selection of Satellite Navigation System in the Autonomous Mode of Positioning

Today, the list of applications that require accurate operational positioning is constantly growing. These tasks include: tasks of managing groups of Autonomous mobile robots, geodetic tasks of high-precision positioning, navigation and monitoring tasks in intelligent transport systems. Satellite navigation systems are a data source for operational positioning in such tasks. Today, global and local satellite navigation systems are actively used: GPS, GLONASS, BeiDou, Galileo. They are characterized by different completeness of satellite constellation deployment, which determines the accuracy of operational positioning in a particular geographical point, which depends on number of satellites available for observation, as well as the characteristics of the receiver, landscape features, weather conditions and the possibility of using differential corrections. The widespread use of differential corrections at the moment is not possible due to the fact that number of stable operating reference stations is limited - the Earth is covered by them unevenly; reliable data networks necessary for the transmission of differential corrections are also not deployed everywhere; budget versions of single-channel receivers of the navigation signal are widely used, which do not allow the use of differential corrections. In this case, there is a problem of operational choice of the system or a combination of satellite positioning systems, providing the most accurate navigation data. This paper presents a comparison of static and dynamic methods for selecting a system or a combination of satellite positioning systems that provide the most accurate definition of the object's own coordinates when using a single-channel receiver of navigation signals in offline mode. The choice is made on the basis of statistical analysis of data obtained from satellite positioning systems. During the analysis, the results of post-processing of data obtained from satellite navigation systems and refined with the use of differential corrections of navigation data were compared.