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The Precise satellite Positioning System ASG-EUPOS GEOS 2008
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THE PRECISE SATELLITE POSITIONING SYSTEM ASG-EUPOS
Marcin Ryczywolski, Artur Oruba, Marcin Leończyk
ASG-EUPOS National Management Center
The Head Office of Geodesy and Cartography
Wspólna 2 Street, 00-910 Warsaw, POLAND
e-mail: marcin.ryczywolski@gugik.gov.pl
Abstract
Nowadays, the use of the Global Navigation Satellite Systems (GNSS) is the fastest and easiest way to
determine position. Yet, their accuracy is still limited, because it is dependent on a number of various
factors, mostly ionospheric and tropospheric delays. To improve the accuracy of GNSS, the systems
based on reference networks are being built. Such networks consist of a ground control points (called
reference stations) on which signals from GNSS satellites (GPS, GLONASS and in the future also
GALILEO) are being constantly collected. By using differential observation methods, reference
station systems can provide real time corrections that are used by GNSS receivers in the field, to
calculate position with better precision. Such systems may well be used in any applications which
need to determine position with high accuracy and reliability, i.e. geodesy, engineering, surveying,
navigation, fleet management and many more.
The precise satellite positioning system ASG-EUPOS (Active Geodetic Network – EUPOS) is
a project of a reference station system designed for Poland, carried out by the polish authority for
geodesy – Head Office of Geodesy and Cartography. It is also a part of the European Position
Determination System (EUPOS), which has prepared the standards for reference systems for 15
countries in Central and Eastern Europe, in order to establish a unified infrastructure for positioning
services.
The aim of this paper is to present the results obtained so far (February 2008) by the ASG-EUPOS
project in establishing the reference station system in Poland.
1 Introduction
The first polish project to establish the GNSS reference system, called ASG-PL, was carried out by the
Head Office of Geodesy and Cartography (GUGiK) and the Silesian Voivodship in 2004. System
based on this network enabled free access to observational data and automated postprocessing module.
At first the network consisted of six reference stations, but two years later another system for precise
satellite positioning founded on the area of Małopolskie Voivodship has joined the ASG-PL. Network
enlarged by five new reference stations and system extended with a module for real-time corrections
generation, was turned in a regional system for precise positioning for economical purposes. The
details concerning system’s work can be found on web pages: www.asg-pl.pl and
www.gps.malopolska.pl. Simultaneously, the concept based on experience from first pilot project and
some arrangements were being prepared for establishing national reference system, which would be a
part of the region-wide EUPOS initiative.
Date of the 2
nd
January 2007 is a beginning of the ASG-EUPOS (Active Geodetic Network - EUPOS)
project realization. The contract for the building the system has been signed by the Head Office of
Geodesy and Cartography and consortium: WASKO S.A., Geotronics Poland Sp. z o.o. and Trimble
Europe BV. The main goal of building this system is to web-enable corrections for GNSS observations
for satellite receivers and enable precise positioning and navigation in Poland. The reference stations
GEOS 2008 M.Ryczywolski, A. Oruba, M.Leończyk
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will crate the geodetic control network according to the regulations of the act from May 17
th
1989,
Geodetic and Cartographic law. Realization of the project includes also arranging technical service
and also supplying the geodesy and cartography documentation centers with GNSS equipment.
The ASG-EUPOS multifunctional precise satellite positioning system project is realised utilising the
resources of the European Regional Development Fund within the Sectoral Operational Programme
„Improvement of the Competitiveness of Enterprises”. The contract for project subsidising was signed
on the 2nd of August 2005. The Ministry of Regional Development is the Managing Authority, while
Department of European Funds acting within the Ministry of Science and Higher Education is the
Implementing Authority and the General Surveyor of Poland is the Final Beneficiary.
2 System segments an their functionality
The ASG-EUPOS system is composed of three essential segments: the segment of reference stations,
the management segment and the segment of users. Those tree elements are connected in one unified
system, manage to provide precise positioning services for real-time and postprocessing applications.
Figure 1 – The chart of system segments and services.
The first segment consists of reference stations located on the Polish territory (Figure 2). Network
based on this stations fulfill EUPOS requirements such as: regular distribution of the stations, mean
distances between neighboring stations (70 km), assimilation of all existing Polish EPN and IGS
stations. Reference stations are mainly located on the buildings of public institutions. Localizations
were selected by the verification results which concern the possibility of installing the GNSS antenna
(by analyzing observation conditions of GNSS satellites) and the placement of 19-inch rack with
modules: receiving, primary and emergency power, remote control and communication as well as the
possibility to establish communication connections.
According to Figure 2 numbers describing the contents of the segment of reference stations segment
are:
– 76 reference stations built within the realization of project (denoted by triangles), where
67 of them are equipped in GPS module and 8 stations with GPS/GLONASS module;
– 22 existing reference stations joined into the network (denoted by dots), where 16 of them
are equipped in GPS module and 6 stations with GPS/GLONASS module;
– not more than 30 foreign reference stations situated in the border zone, working within
EUPOS System;
The Precise satellite Positioning System ASG-EUPOS GEOS 2008
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– 8 of the stations mentioned above, denoted by squares, are already admissioned into the
EUREF Permanent Network (EPN);
– 7 new reference stations, denoted by squares, are planned to be admissioned into the EPN.
Figure 2 – Distribution of ASG-EUPOS system reference stations.
The GPS stations receiving module is equipped with Trimble NetRS receivers and Trimble Zephyr
Geodetic I antenna with TZGD radome (TRM41249.00 TZGD). The GPS/GLONASS stations
receiving module is equipped with Trimble NetR5 receivers with Trimble Zephyr Geodetic II antenna
with TZGD radome (TRM55971.00 TZGD).
This segment collects observational data from navigational satellites and transfers it, in real-time, as
a raw data to management centers. For this purpose to each reference stations a secure teleinformation
connection has been established. Data is transferred using TCP/IP protocol with the sample frequency
of 1Hz (every 1 second). Observations are also stored in the interior memory of GNSS receivers, in
case of any problems with network connection, waiting to be transferred.
The management segment is based on two management centers: in Warsaw and Katowice (denoted by
circles on Figure 2). The purpose for creating two management centers is to prevent from
discontinuation of services provided, in case of disabling one of the centers. They are fully correlated
in operations, so the calculations can be easily be switched between those centers. Management
centers are mostly responsible for services provided by the ASG-EUPOS system which are: NawGeo,
NawGis and KodGis as real-time services and PozGeo and PozGeo D as services for postprocessing.
GEOS 2008 M.Ryczywolski, A. Oruba, M.Leończyk
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Figure 3 – Example of antennas mounting for the ASG-EUPOS reference stations.
The real-time services enable differential corrections for surveyors in field, calculated from
observational data coming from the reference stations. The calculation segment for real-time services
will be realised by Trimble Infrastructure Software™ that is installed in both Management Centres.
This task will be realised by GPSNet and RTKNet modules as well as the NTRIP Caster application.
Postprocessing services allow user to download observations from given reference stations in RINEX
format and virtual station’s position or to upload user’s observational file (in RINEX format) for
processing. This module work in automatic mode, with possibility of the operators’ intervention in
case of a need for manual calculations. The calculation segment for postprocessing mode will be
installed in Management Centres, available to users through the web page and based on Automatic
Postprocessing Software for Trimble Application. The overall characteristic of the real-time services
offered in ASG-EUPOS system is introduced in Table 1.
Table 1 – Services provide by ASG-EUPOS system.
The maintenance of reference system and the control of correctness of its realisation is provided in
ASG-EUPOS system. For that purpose an autonomous calculating system based on the Bernese GNSS
Software v. 5.0 is launched. The task of this service is to make calculations of the whole ASG-EUPOS
reference stations network according to the calculation standards applied by the EPN network’s
The Precise satellite Positioning System ASG-EUPOS GEOS 2008
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centres of analyses. The results of these analyses will enable the control of the reference stations’
coordinates stability and will constitute the base to carry out actions in case of occurrences of essential
transitions in antennas’ phase centres position.
The user segment will comprise of mobile receivers equipped with GSM/GPRS module. Such
a configuration will enable direct use of real-time services (NawGeo, NawGis and KodGis) of the
ASG-EUPOS System. The software of the mobile receivers’ is to enable the direct determination of
point coordinates in terrain in national spatial reference fames: EUREF 89, 1965, 1992, 2000 and
1965, and also the normal heights in Kronstadt 86 frame. The user will have access to the
postprocessing mode calculation services (PozGeo and PozGeo D) through the system’s web page. In
further future, with the eventual increasing number of system usres, it is also planned to establish FM
transmission.
3 Project realization
On the 2
nd
of August 2005 a contract was signed for subsiding of the construction of the ASG-EUPOS
precise satellite positioning system utilizing the resources of the European Regional Development
Fund within the Sectoral Operational Programme “Improvement of the Competitiveness of
Enterprises” 2004-2006 (SOP-ICE). The project has been realised within Priority 1 – Enhancement of
knowledge based economy business environment, Task 1.5. Development of a system of
entrepreneurs’ access to information and public services on-line. The Ministry of Regional
Development is the Management Authority, the Department of European Funds acting within the
Ministry of Science and Higher Education is the Implementing Authority. The General Surveyor of
Poland is the Final Beneficiary, who, in order to support the project, established the Project Steering
Committee and two counselling bodies: the Programme Council of the Project and the Team of
Experts.
The practical realisation of the ASG-EUPOS System has begun with the beginning of 2007 after
signing the 2nd of January the contract for founding the system by consortium: WASKO S.A,
Geotronics Poland Sp. z o.o. and Trimble Europe BV. The realisation of the contract has been divided,
for technical reasons, into four stages:
Stage 1 – consisting of: the delivery of 30 dual-frequency GPS receivers with the equipment and
software of the reference stations, the delivery of servers, computer and telecommunication
equipment, system and application software, as well as the delivery of 15 dual-frequency GPS
receivers with equipment and software for RTK/DGPS field measurements;
Stage 2 – consisting of: delivery of 40 dual-frequency GPS receivers and 8 dual-frequency
GPS/GLONASS receivers with the equipment and software for the reference station, mounting
of reference stations in 75 locations, delivery and installation of supplementary equipment,
installation of servers, computer and telecommunication equipment, system and application
software in Management Centres, connecting all the system elements and training of the
personnel operating the stations and positioning services. 50 dual-frequency GPS receivers will
also be provided, with equipment and software for RTK/DGPS field measurements and training
of operating personnel will be conducted;
Stage 3 – consisting of: launching of real-time and postprocessing precise positioning services,
preparing the documentation for services, preparing the reference station installation
documentation, and also training of the staff,
Stage 4 – consisting of: plugging the border stations in and connecting the National Management
Centre with National Management Centres in neighbouring countries, testing and authorisation
of the precise positioning system in Poland.
GEOS 2008 M.Ryczywolski, A. Oruba, M.Leończyk
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According to the accepted schedule Stage 1 has been finished in March 2007, Stage 2 in June 2007
and Stage 3 by the February 2009. The ASG-EUPOS System after the audit completion should be
available to the users with the first half of 2008.
4 Conclusions
The existence of multifunctional systems for precise satellite positioning that are used by public
institutions, entrepreneurs and citizens is presently an essential element of countries development.
Such system for Poland is going to be finally established in May 2008. Already the system is
functioning in test mode to detect any eventual instability.The realisation of the ASG-EUPOS system
also requires the coordination of operations with the neighbouring countries, especially in the scope of
common technical standards and the exchange of observational data from border stations. It is also
important because of anticipation for lunching of EUPOS system. Under the EUPOS standards
participating countries will apply a unified technical standard and will render the data accessible from
the border reference stations
References
[1] ASG-EUPOS (2007) Information about the ASG-EUPOS system, January 2007,
http://www.asgeupos.pl/
[2] ASG-PL/EUPOS – Polish part of the EUPOS system, Head Office of Geodesy and Cartogra-
phy, 2004 (in Polish).
[3] Bosy J., Graszka W., Leończyk M. (2007), ASG-EUPOS – A Multifunctional Precise Satellite
System in Poland, European Journal of Navigation, vol. 5(4) September 2007, p.2-6 (in Eng-
lish).
[4] EUPOS (2007), EUPOS – General Information, January 2007, http://www.eupos.org/
[5] GUGiK (2006), ASG-EUPOS - a multifunctional precise satellite positioning system – infor-
mation brochure, Head Office of Geodesy and Cartography, Warsaw 2006 (in Polish)
[6] Technical project of multifunctional precise satellite positioning system ASG-EUPOS in Po-
land, Head Office of Geodesy and Cartography, 2005 (in Polish).
[7] The offer of the consortium represented by WASKO S.A. to build a multifunctional precise sat-
ellite positioning system ASG-EUPOS in Poland, 2006 (in Polish).
[8] Realization technical project of the consortium represented by WASKO S.A. to build
a multifunctional precise satellite positioning system ASG-EUPOS in Poland, 2007 (in Polish).
[9] Graszka W. (2007) Multifunctional precise satellite positioning system ASG-EUPOS, Geodeta,
Geoinformational Magazine Nr 2(141) February 2007 p.4-8, (in Polish).
