THE PRECISE SATELLITE POSITIONING SYSTEM ASG EUPOS AND ITS POTENTIAL APPLICATIONS

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1 Główny Urząd Geodezji i Kartografii ul. Wspólna 2, Warszawa tel fax e mail: gugik@gugik.gov.pl The Project is co financed by the European Union, European Regional Development Fund VII th Transport Systems Telematics International Conference October 2007, Katowice Ustroń, Poland THE PRECISE SATELLITE POSITIONING SYSTEM ASG EUPOS AND ITS POTENTIAL APPLICATIONS IN TRANSPORT MOŻLIWOŚCI WYKORZYSTANIA SYSTEMU PRECYZYJNEGO POZYCJONOWANIA SATELITARNEGO ASG EUPOS W TRANSPORCIE ARTUR ORUBA ASG EUPOS National Management Center Head Office of Geodesy and Cartography Wspólna 2, Warszawa, Poland tel e mail: artur.oruba@gugik.gov.pl ABSTRACT The project of building a unified precise satellite ing system in Poland, carried out by the Head Office of Geodesy and Cartography, is based upon the idea of European Position Determination System (EUPOS). The ASG EUPOS system uses a network of GNSS reference stations to enable the user determine real time with high precision using differential observation methods. Such system may well be used in any applications that need differential (ie. DGNSS) determination, such as fleet management, navigation and many more. STRESZCZENIE Realizowany przez Główny Urząd Geodezji i Kartografii projekt budowy systemu precyzyjnego pozycjonowania satelitarnego na obszarze Polski oparty jest na idei ogólnoeuropejskiego systemu EUPOS. Polski system ASG EUPOS wykorzystuje sieć naziemnych stacji referencyjnych GNSS w celu umożliwienia jego użytkownikom określenia z wysoką dokładnością pozycji w czasie rzeczywistym, z wykorzystaniem różnicowych metod pomiaru. System ten może zostać z powodzeniem wykorzystany wszędzie tam, gdzie wymagane jest zastosowanie metod różnicowych do zwiększenia dokładności (np. DGNSS), między innymi w zarządzaniu flotą pojazdów, nawigacji i in.

2 THE BACKGROUND In the last few years the demand on various ing services has grown very significantly. This can be associated with the increase of social awareness of actual possibility to precisely determine the of certain objects an Earth surface. Therefore also more and more possible applications of ing have been found recently. The most popular way to determinee the in a global reference frame nowadays is to use a GPS (or more generally GNSS Global Navigation Satellite System) receiver that does it for us. The principle of ing with GNSS satellites is based upon distances between the receiver (antennaa phase center) and satellites, which coordinates are known (fig. 1). But unfortunately the precision of that so called absolute estimation is dependent on a large number of various factors. Fig. 1. The principle of determination in GNSS systems. Knowing the of satellites and measuring the distances between satellites and the GNSS receiver at the same time one can calculate the coordinates of this receiver in a global reference frame. To reduce the influence of thesee factors differential methods of observation are used. They allow us to significantly reducee errors due to unmodeledd influence of atmospheree and ionosphere on the measured distance to satellites, limited precision of GNSS satellites coordinates, satellite constellation shape, Earth tidal effects, possible political caused disturbances of the satellite systems (ie. selective availability in GPS), etc. The essence of differential measurements is based on the assumption, that the errors mentioned above are the same on a specified area of the Earth and can be determined and eliminated by comparing with satellite observations carried out at a point with known coordinates, called a reference station, with observations carried out in the specified point. As an example, one can estimate the mean precision of absolute determination by GPS system around 5 7 meters, while using differential methods the precision increases even up to few centimeters (in real time measurements) and is mostly dependent on the distance from a reference station [5]. To use various differential determination techniques like RTK (Real Time Kinematics) or DGNSS (Differential GNSS) at a large area, such as Poland or Central Europe, a unified network of GNSS reference stations has to be established. Such network, based on the same referencee system and same standards, called EUPOS (European Position Determination System) is planned to be developed in Central and Eastern Europe [4]. In the area of Poland, a cooperating system called ASG EUPOS (Active Geodetic Network EUPOS) is being built [2]. Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 2

3 THE ASG EUPOS SYSTEM STRUCTURE The ASG EUPOS system is based on a network of ground control points on which signals from GNSS (GPS, GLONASS and in the future also GALILEO) satellites are being constantly observed. It consists of 94 reference stations in Poland and up to 30 stations in neighboring countries that take part in the EUPOS project [2] [3] [5] [6]. According to the EUPOS standards, the ASG EUPOS system is being built based on the following rules [4]: the mean distance between neighboring reference stations equals around 70 km, the stations are regularly distributed, creating a uniform network that covers whole Polish territory, the network assimilates all existing Polish EPN and IGS stations, reference stations coordinates are being estimated in the ETRS 89 (European Terrestrial Reference System 89) and in local coordinate systems used in Poland, reference stations observe GPS and GLONASS satellites, and are compatible with the GALILEO system when it is available, precise dual frequency GNSS receivers are being used on all the stations, the of all ground control points will be regularly controlled. Additionally, the system is based on the rule of open architecture, which assures the possibility to increase not only the number of reference stations included, but also the functionality of services offered [8]. The whole system is planned to be a fundamental reference to all the measurements in Polish national reference frames. The system provides a uniform and homogenous spatial reference which is also available remotely and therefore enables to use this uniform geodetic framework even outside classic geodetic applications. The raw observational data from reference stations are being constantly transferred via high speed WAN network to National Management Centers in Katowice and Warsaw [2] [3] [5] [9]. There all the processing takes place, including the control of system stability and provision of services. The services provided (tab. 1) are divided roughly into the real time and postprocessing ones. Those based on the real time estimation of user s are related to calculation of DGNSS or RTK corrections. The postprocessing services provide very precise information, but require long enough observation sets and cannot be used in real time applications. General division Service name Measurements method Data transmission Estimated precision Minimum hardware requirements Real time services NAWGIS KODGIS Kinematic (DGNSS) Internet/ GSM/ FM m m L1 GPS receiver, communication module L1 GPS receiver, communication module NAWGEO Kinematic (RTK) 0.03 m (horiz.) 0.05 m (vert.) L1/L2 GPS receiver, communication module Postprocessing services POZGEO POZGEO D Static/ kinematic (postprocessing) Internet/ hardcopy m L1 GPS receiver Tab. 1. Services provided by the ASG EUPOS system to the users [2] [3] [5] [6]. 1 FM transmission is planned in further future and is correlated with the eventual increasing number of system users. Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 3

4 Below, an additional structural graph (fig. 2) presents the main ASG EUPOS system segments and relations between them. Fig. 2. The ASG EUPOS structure and relations between specific segments. ADVANTAGES OF IMPLEMENTING THE SYSTEM Nowadays many applications that require precise ing use differential methods to increase precision and reliability of solutions. One of the most expensive aspectss of those applications is to actually calculate and properly distribute real time corrections. The ASG EUPOS, while being nationwide and easily accessible from any place and at any time in the area of Poland, gives the possibility to reduce costs associated with distribution of corrections. While providing a standardized RTCM (Radio Technical Commision For Marine Services) corrections format and universal transmissionn ways the same as in other EUPOS based systemss in neighboring countries (Internet, GSM, also planned through FM) the system assures compatibility of hardware and software used to develop other systems benefitting from satellite estimations. Another important feature of the ASG EUPOS system is the uniform reference frame in which the is determined the specific realization of ETRS 89 that is widely used in the whole Europe, especially in the countries that take part in the EUPOS project. This assures that when crossing borders, no additional calculations need to be done to uniformly determine or to navigate with a single navigation system or map. Advancedd methods of RTK corrections estimation, such as VRS (Virtual Reference Station), FKP (ger. Flächenkorrekturparameter) or MAX/iMAX (Master Auxiliary Concept), assure high precision of satellite ing, no worse than 3 cm horizontally and 5 cm vertically, inside the reference stations network [2] [3] [5] [6]. Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 4

5 THE ASG EUPOS PROJECT REALIZATION The main goal of the ASG EUPOS project is to establish a nationwide network of ground reference stations and a Management Center for sharing corrections necessary for determining the from GNSS observations with high precision in Poland. As a part of the region wide EUPOS project, the ASG EUPOS project started on the 2 nd of August 2005 when a new contract for subsiding the build of the ASG EUPOS system was signed. The project is being financed within the EU Sectoral Operational Programme Improvement of the Competitiveness of Enterprises (SOP ICE), Measure 1.5 Development of a system of entrepreneurs access to information and public services on line. The Managing Authority is the Ministry of Regional Development, the Department of European Funds within the Ministry of Science and Higher Education implements the project. The President of the Head Office of Geodesy and Cartography, as the Final Recipient, established the project Steering Committee and two counseling bodies: the Programme Council and the Team of Experts. [3] [5] [6] In the beginning of 2007 (January, 2 nd ) a final contract for establishing the ASG EUPOS system, including the delivery of a number of GPS mobile survey sets, was signed [3] [5] [6]. This contract additionally includes connecting the existing and foreign border reference stations to the system. The main stages of the ASG EUPOS project have been listed below in table 2. July 2004 August 2005 September 2005 January 2006 July 2006 August 2006 January 2007 April May 2007 June September 2007 September October 2007 October November 2007 December 2007 January 2008 the ASG EUPOS system general concept signing of the contract for subsiding the build of the system the beginning of the ASG EUPOS project technical project concept establishment of the National Management Center the system establishment put out to tender signing of the contract on the system establishment verification of reference stations location reference stations installation procedure the beginning of the system testing procedure the calibration campaign finalization of the ASG EUPOS project full system operability Tab. 2. The ASG EUPOS project realization schedule [2] [6]. PRESENT AND POTENTIAL APPLICATIONS IN TRANSPORTATION SYSTEMS Most issues related to transportation, such as traffic guidance, fleet management, telematics in traffic, navigation, etc. require spatial reference to describe them [7]. Usually in those applications, local GNSS reference stations are needed to produce DGNSS corrections in real time. But various transportation applications need different precision and availability levels of services. The ASG EUPOS system enables adaptation of sufficient services in various transportation applications, as required. The existing similar to ours German SAPOS ing system [8] is being used in various systems and applications associated with transport. It is commonly known that only widespread reference systems like Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 5

6 SAPOS or EUPOS are profitable and economically reasonable [7]. That is why the ASG EUPOS system might be well used in the following transportation applications, providing cost effective solution for transport related systems: municipal transportation vehicles scheduling, control and guidance. In this case the GNSS relative ing provided by ASG EUPOS could increase punctuality and quality of services in bus and tram networks, increase flexibility in changing the routes, enable traffic lights control and dynamic passenger directed information on connections. This solution could significantly reduce costs compared to very ineffective traditional methods of human based (manual) vehicle control systems. As an example, the SAPOS system plays an important role in the BVG (ger. Berliner Verkehrsbetriebe) Vehicle Scheduling and Control System [7]. public security fleet management. Similar to potential applications in municipal transport, the system gives the possibility to enchance public security effectiveness by helping the police with precise traffic control, changes of routes while escorting important visitors, navigation and reporting on the fleet of police cars. In Germany, Berlin this has been implemented in ZVkD (Central Police Traffic Service) [7]. ambulance fleet management. Relative ing (ie. ASG EUPOS system), uniform in such a large area as Poland, gives the opportunity to navigate and control the of all ambulance vehicles in the selected area. Additional sensors, integrated in one multifunctional system, ie. SWD KPR (Commanding Support System of Krakow Emergency Service), enable full control over ambulance vehicles and crew. This leads to cost reduction and work optimization, as well as integration with other rescue services [1]. precise lane traffic steering. Positioning with ASG EUPOS gives the opportunity to use precise ing data to navigate vehicles in traffic and collect information on traffic intensity and flow to adjust infrastructure to sufficient needs. marine navigation in shipyards and river transport. High precision of calculated with the ASG EUPOS corrections within various available services is crucial when navigating in shallow waters or shipyards. railway transport management and scheduling. Real time of trains enables more accurate and remote management, as well as always up to date information on timetables and possible train delays for passengers. Because the ASG EUPOS system is not yet fully operational, many possible applications, including those in the area of transport, haven t been currently revealed. REFERENCES [1] ANTOSIEWICZ M. (2007), Wykorzystanie systemów pozycjonowania precyzyjnego dla potrzeb ratownictwa (The use of precise ing systems in rescue applications), presentation on the regional conference Applications of the multifunctional precise satellite ing system ASG EUPOS, Warszawa, 21 March 2007 [2] ASG EUPOS (2007), Information about the ASG EUPOS system, October 2007, [3] BOSY J., GRASZKA W., LEOŃCZYK M. (2007), ASG EUPOS A multifunctional precise satellite ing system in Poland, European Journal of Navigation, vol. 5 (4) September 2007, pp. 2 6 [4] EUPOS (2007), EUPOS General Information, October 2007, Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 6

7 [5] GRASZKA W. (2007) Wielofunkcyjny system precyzyjnego pozycjonowania satelitarnego ASG EUPOS (Multifunctional precise satellite ing system ASG EUPOS), Geodeta, Geoinformational Magazine, vol. 2 (141), Feb. 2007, pp. 4 8 [6] GUGiK (2006), ASG EUPOS A multifunctional precise satellite ing system information brochure, The Head Office Of Geodesy and Cartography, Warszawa 2006 [7] ROSENTHAL G. (2005), Optimization of traffic management and traffic telematics by multifunctional GNSS services, presentation at METROPOLIS 05 BERLIN The future of the City, VIII METROPOLIS World Congress, Berlin, May 2005 [8] SAPOS (2007), The SAPOS Booklet and Flyer, October 2007, [9] WASKO S. A. (2007), Wykonawczy projekt techniczny wielofunkcyjnego systemu precyzyjnego pozycjonowania satelitarnego ASG EUPOS (Technical project of multifunctional precise satellite ing system ASG EUPOS), WASKO S. A., Geotronics Sp. z o. o., Trimble BV, 2007 Artur Oruba, The precise satellite ing system ASG EUPOS and its potential applications in transport 7