SPACE APPLI 2012 EGNOS2ROAD: assessing benefits for road applications

Transcription

1 SPACE APPLI 2012 EGNOS2ROAD: assessing benefits for road applications Fiammetta Diani Market Development Officer European GNSS Agency Rue de la Loi 56 B-1049 Brussels (Belgium) Philippe Hamet Policy officer DG MOVE European Commission 28 rue De Mot 1040 Brussels (Belgium) I. ABSTRACT EGNOS2ROAD (E2R) is a project funded by the European Commission, Directorate General for Enterprise and Industry, to assess and quantify EGNOS 1 benefits for Road Applications, by means of an exhaustive trial, involving final users and focusing on their decision-making process. The project has been performed in 2011 and finalised recently. E2R selected "Road User Charging" and "Tracking and Tracing of Professional Fleets" as main applications that can benefit from EGNOS. Two final users have been active partners proposing their business cases, decision criteria and assessing the results of the trial: the motorway operator SAT and the Mobility Agency of Rome (RSM), both located in Italy. E2R performed a trial using mass market automotive receivers, different kind of antennas and comparing standard GPS 2 positioning with: GPS plus EGNOS: the corrections are received via Signal in Space (SiS) GPS plus EGNOS/EDAS (EGNOS Data Access Service): the corrections are received via ground communication means. In addition, E2R tested EGNOS performances obtained via the LoCation Server (LCS), a navigation solution developed by Telespazio delivering a commercial service based on EGNOS, optimised for road applications. LCS processes the EGNOS integrity providing the qualification/confidence in the position information. Sanna Kuukka, Policy Officer DG ENTR European Commission B-1049 Brussels (Belgium) Antonella Di Fazio GNSS-lnfomobility Telespazio Via Tiburtina, Rome (Italy) The data and analysis performed in the trial showed positive results: the position accuracy is enhanced by EGNOS on average and in all the critical cases identified by the users. As a result, the two users recommended the use of EGNOS in all new GNSS systems they will introduce in their businesses. The qualification/confidence in the position information is available in more than 96% of the cases and provides a protection level of around 8-10 meters, being technically suitable for some applications identified by the users. This paper describes the methodology used by E2R and illustrates the main results obtained, both from technical and users perspective. Keywords: satellite navigation, EGNOS, services, integrity and augmentation, guaranteed and precise positioning, performance comparison, benefits, road charging, road professional fleets, tracking and tracing. II. SETTING THE SCENE The road sector is among the largest markets for GNSS 3 applications. Satellite navigation technology is widely used in the automotive market, for mass-market and professional applications. EGNOS, the European Geostationary Navigation Overlay Service, is a SBAS (Satellite Based Augmentation System) that improves the GPS position accuracy and provides integrity information over Europe and the Mediterranean area. EGNOS is operational and offers three services: 1 European Geostationary Navigation Overlay Service 2 Global Positioning System 3 Global Navigation Satellite Systems

2 EGNOS Open Service (EGNOS OS) is made available to users equipped with GPS/EGNOS receivers via the satellites signal (i.e. the SiS). EGNOS Safety Of Life (EGNOS SOL) is designed for safety critical applications in civil aviation, in accordance to the SARPs 4 criteria and in compliance with the RTCA 5 Minimum Operational Performance Standards (MOPS) for airborne navigation equipment using the GPS augmented by SBAS. EGNOS Commercial Service (EGNOS CS) is distributed to professional users through terrestrial networks via a server named EDAS 6. The EDAS server broadcasts EGNOS data to software solutions that provide added value services for improving the availability and the position accuracy of the EGNOS OS. Moreover, EGNOS CS/EDAS enables to qualify and guarantee the GPS position information by exploiting the EGNOS integrity. Following the EC call "Assessment of the utilisation of EGNOS in the road transport domain" (CALL FOR TENDER NO. TREN/G4/ ), in the period from October 2010 up to July 2011, the project E2R has assessed the added value/benefits of EGNOS OS and EGNOS CS/EDAS, compared with the GPS for the road sector, and specifically for two applications: road tolling tracking & tracing of professional fleets, in urban and extra-urban operational business cases. For this purpose, E2R has carried out: extensive trials in various road environments (urban and extra-urban) representing real operational scenarios and business cases technical assessment of the performances through the analysis of the data collected during the trials business validation through market analysis. E2R also performed an assessment of the use/value of EGNOS integrity, in terms of technical, business and legal aspects. In particular the assessment is done in case of different processing, by using EGNOS OS (i.e. the SBAS messages from the SiS), EGNOS CS/EDAS (i.e. the SBAS messages from EDAS) and by using EGNOS SoL (i.e. the SBAS messages from the SiS and according to SoL implementation). E2R team was composed of four Italian companies, including Telespazio (TPZ) providing the Satellite Navigation and EGNOS/Galileo expertise, Magneti Marelli (MM) providing the in-car telematics expertise, Società Autostrada Tirrenica (SAT) representing the extra-urban 4 The Standards and Recommended Practices (SARPs) are the GNSS requirements for Civil Aviation use defined by ICAO (International Civil Aviation Organization) 5 Radio Technical Commission for Aeronautics 6 EGNOS Data Access Service road operator and Roma Servizi per la Mobilità (RSM) representing the urban road operator. The team was supported by consultants for the market and legal aspects. E2R outcome is an independent position concerning the use/value of EGNOS services in the perspective of Galileo for the two considered road applications, elaborated on the basis of the results of the performed analyses and supported by a validation from the operational and business perspectives. E2R outcomes have a more general validity: in fact, E2R concepts and results, tailored on SAT and RSM specific business cases, are applicable to any other extraurban and urban operators, thus can be extended to other Italian/European road networks and cities. III. E2R BUSINESS CASES E2R market analysis relies on the evaluation of the technical results of the trials upon the operational criteria defined by the two road operators, according to their needs in their real/concrete business cases. Thus the analysis is tuned on the concrete business cases identified by SAT and RSM. In E2R, two business cases are identified for SAT and four business cases for RSM, as well representing the possible business cases for an extra-urban and a urban road operator respectively. A. Extra-urban road operator/sat business cases The following two business cases are identified and considered in E2R, representing the possible business cases for an extra-urban road operator: TC Road charging, related to the implementation of the Electronic Toll Collection (ETC) systems on motorways. TC 2 - Tracking & tracing of third-party service fleets, i.e. the specialised third-party fleets subcontracted by the road operator to perform road maintenance and monitoring operations. The road operator has the need to track & trace such operations, for supervision/control and administration purposes. Tracking & tracing is done by means of satellite navigation based devices installed on the service vehicles, data are used to control the subcontract service performance and validate the invoices issued by the third party. B. Urban road operator/rsm business cases The following four business cases are identified and considered in E2R, representing the possible business cases for a urban road operator: COA - Tourist Coaches Electronic Permit, related to the monitoring of tourist coaches traffic, according to their specific regulation and needs. Presently, this is done on a paper-permit basis, however the possible use of GNSS is under evaluation. LTZ - Limited Traffic Zones, related to the monitoring of vehicles transiting within specific urban areas; this 7 Toll Charger

3 application is not presently feasible with GPS, due to its incapability to provide a guaranteed positioning. LPT - Local Public Transport, related to the monitoring of buses for public transport. This is presently done via a GPS-based AVL/AVM 8 system (in this respect RSM is interested to evaluate possible monitoring service enhancement/additional benefits thanks to EGNOS). GOODS - Goods Delivery, related to the monitoring of vehicles for urban logistics. Presently such application is not possible in Rome, due to the absence of a suitable regulation for freight delivery in the urban areas. However, RSM considers it interesting as such regulations are already in place in other EU Cities and as a possible future use case of EGNOS in Rome. IV. METHODOLOGY E2R has been deployed through various sequential steps: The first step: the identification of the business cases for the two road operators (i.e. SAT/extra-urban and RSM/urban, as above detailed), and for each of them the identification of the possible added value of EGNOS features (i.e. accuracy, availability, guarantee) with respect to GPS. The second step: the execution of trial campaign (for EGNOS OS and EGNOS CS/EDAS only) targeted on the business cases and focused on the added value identified before. The trial campaigns are completed with a detailed technical analysis, aimed at quantifying in terms of performance indicators the EGNOS differentiator/advantage with respect to GPS. The third step: a technical versus operational analysis, and performance indicators before quantified are considered in relation to the operational needs and procedures (taking into account present GPS usage already in some business cases). The performance indicators obtained in previous steps have allowed the road operator to appreciate in which business case/condition EGNOS added value is able to generate economic benefits. Specifically for these business cases/conditions, the fourth step has been to elaborate a market analysis to evaluate the relevant business feasibility by means of business plans. A. Methodology for the trial campaigns and technical data analyses The figure 1 shows the architecture and technology used in E2R trials. The OBE (On-Board Equipment) is derived from the T- Box, which is a MM commercial product for telematics/vehicle tracking/virtual tolling applications (shown in the figure 2). E2R trials are carried out using four T-Box units, two pairs of them integrating two different 8 Automatic Vehicle Localization/Automatic Vehicle Monitoring GPS/EGNOS receivers and configured to use GPS and GPS + EGNOS OS respectively. Two types of receivers are used all along the trials: STA2058-Teseo U-blox LEA 5T selected in the frame of the project, being typical massmarket chipsets used in serial OBEs for automotive GNSS applications. Thus, four T-Box units are used in the E2R field trials: T-Box integrating a u-blox5 receiver configured to be GPS-only T-Box integrating a u-blox5 receiver configured to be GPS+ EGNOS T-Box integrating a Teseo receiver configured to be GPS-only T-Box integrating a Teseo receiver configured to be GPS + EGNOS. Moreover trials are performed with two configurations of antennas and two different vehicle types (a mass-market car9 and a commercial vehicle10): a NovAtel 702-GG L1L2 amplified antenna for professional applications a standard patch antenna for automotive applications. A true path/reference trajectory is calculated in postprocessing, through a kinematic differential GPS method, by using GPS L1 and L2 carrier phase measurements, combined with INS (Inertial Navigation System) measurements. The differential GPS L1 and L2 carrier measurements are collected using a reference receiver installed near each test location with an inter-receiver distance not exceeding 20 km. The GPS reference receiver is geo-referenced via a dedicated GPS network solution (based on a continuous/24h at least for two days data collection campaign). A NovAtel FLEXG2- V2-L1L2 is used as GPS reference with a NovAtel dual frequency antenna (GPS-702GG). An integrated precision GPS/INS system (OxTS 11 RT2002 dual frequency GPS/INS system) is used as rover. The combination with INS is aimed at having smooth trajectories free from jumps, even in difficult GPS environments 12. The E2R architecture enables to perform trials with EGNOS OS and with EGNOS CS/EDAS at the same time. In fact the implementation of EGNOS CS/EDAS is done in real-time in LCS (connected to EDAS), by using the raw 9 A FIAT Panda 10 A FIAT Doblò 11 Oxford Technical Solutions 12 In fact the INS measurements are used in the true path calculation to complement the GPS L1 and L2 carrier measurements in difficult environments (i.e. in high multipath conditions or lack of satellite visibility, such as in urban or tree-dense environments).

4 data received from the T-Box and the data from EDAS (in real-time 13 ). LCS is based on a TPZ patented algorithm, designed and developed on the basis of MOPS (Minimum Operational Performance Standards) RTCA/DO-229D suitably customized for road environments. Basically, LCS receives the positions, time and raw data from the T-Box via GPRS 14, implements the EGNOS CS/EDAS processing using the EGNOS messages (from EDAS) and returns: EGNOS corrected positions Protection Levels, i.e. HPL (Horizontal Protection Level) and VPL (Vertical Protection Level). The four T-Box units and the GPS/INS RT2002 OxTS system are connected to one external GPS antenna. The rationale for using a common antenna instead of five antennas (one per receiver) is to avoid offsets and thus to have a higher control of the tests conditions. The five units receive GPS signals from the amplified antenna via a GPS splitter connected to the antenna by a NovAtel cable. Adapters/connectors are used for the connections as needed. In order to feed the antenna, the splitter is able to pass the DC 15 from an output port and is able to block the DC to the remaining output ports. A suitable splitter, the GPS SourceS18-A16-SF, is chosen 16. The overall system is powered supplied by a car battery with adequate power. The data from the four T-Box units are sent to LCS via GPRS, as above detailed, for EGNOS CS/EDAS processing, and stored for technical analysis. The measurements of the RT2002 GPS/INS system are collected on a dedicated laptop PC. The figures 2, 3, 4, 5, 6 and 7 present some views of the tested equipment and antennas installed on the roof of the vehicles. Figure 2. MM T-Box for telematics/virtual tolling applications Figure 3. NovAtel and standard antennas on top of the SAT vehicle Figure 1. E2R architecture and technology for the use of EGNOS OS and EGNOS CS/EDAS 13 EDAS in its present configuration does not provide historical data to be used in post processing. 14 General Packet Radio Service 15 Direct Current 16 In order to take into account the power loss due to the involved cable connections and the adapters a power gain of 16db is provided to the signal by the splitter itself. Figure 4. OBEs dashboard as installed in the vehicle rear

5 Figure 5. OBE dashboard and battery in SAT vehicle boot Figure 6. IMU onboard RSM vehicle and NovAtel antenna signal splitter on back seat Figure 7. NovAtel and standard antennas on top of the RSM vehicle The following data sets are collected during the trials: Raw measurements from the GPS/INS system Positions & raw measurements from the two OBEs, GPS and GPS + EGNOS respectively EGNOS corrected positions, HPL and VPL returned by the LCS. These data sets collected are analysed, using both commercial and freely available software packages, including: The Bernese software ( version 5.0 for the georeferencing data processing. NovAtel s GrafNav/GrafNet for determining the GPS/INS reference trajectory. The key advantage of the GrafNav is the great flexibility in the coordinate output file export, which can be customized for further processing and/or visualization through other tools ( tm) GPSTk ( which is an open source suite of fundamental and advanced GPS processing algorithms developed by the University of Texas. The library provides functions including RINEX 17 I/O, ephemeris calculation, atmospheric refraction models, and positioning algorithms. The applications include cycle slip detection and removal, calculation of the Total Electron Content (TEC) of the ionosphere, and RINEX file manipulation. Based on the GPSTk library, Telespazio has developed routines to be personalised and adapted for being used in the performed test analysis PEGASUS ( is a tool developed by EUROCONTROL for the analysis of static and dynamic GNSS data. PEGASUS is used to compute the NSE (Navigation System Error) giving in input the true path obtained with the GrafNav/GrafNet. Statistical analysis is done on the values of HNSE (Horizontal Navigation System Error) linked to the accuracy of the position (i.e. the horizontal accuracy of the position with respect to a reference trajectory/true path) and the protection levels providing the qualification/level of confidence in the position (obtained through the processing of EGNOS integrity). B. Methodology for the market analyses Specifically concerning the market analyses, the objective has been to provide the necessary economic basis to assess whether EGNOS services are interesting from the business perspective for SAT/extra-urban road operator and RSM/urban road operator. The assessment has relied on the results of technical analysis of the data collected during the extensive trial campaign executed in E2R. The performed analyses have focused on the identified business cases for SAT/extra-urban road operator and RSM/urban road operator, considering a time lag of 10 years starting from 2011 (i.e ). EGNOS OS and EGNOS CS/EDAS added value has been evaluated with respect to GPS (since E2R is focused on 17 Receiver INdependent Exchange format

6 the use of GPS + EGNOS with respect to the GPS, it is assumed that the two operators already use GPS). The business plans have developed for EGNOS OS, and EGNOS CS/EDAS. More specifically, the analysis has considered the use of 18 : GPS + EGNOS OS GPS + EGNOS OS + EGNOS CS/EDAS. Three possible implementations/architectures for the use of EGNOS services are considered in E2R: By means of EGNOS CS/EDAS making use of: o o The EDAS services presently available 19. In this case the EGNOS integrity processing is done in the Service Centre 20 connected to the EDAS to get SBAS data. The EDAS service not presently available but expected to be available 21. In this case the EGNOS integrity processing is done in the OBE connected to the EDAS to get SBAS data. By means of EGNOS SoL making use of SBAS data broadcasted by the SiS. In this case the EGNOS integrity processing is done in the OBE. The market analysis is deployed in quantitative terms, through the development of two business plans, one for SAT and one for RSM. These two business plans have been elaborated on the basis of concrete data of the two road operators, and, as above detailed, assuming that the two operators already use a GPS-based system and thus estimate the differential elements 22. The capability to distinguish the position of the vehicle just after/before a motorway intersection or ramp near the gates. The next figure shows the E2R trials results in the case of SAT close/parallel roads. E2R has verified EGNOS enhanced performances in the selected critical points of the present SAT stretches, on the basis of the results of the technical analysis of the data collected during the trials. From the above plots, it appears that for the selected critical point representing the occurrence of close/parallel roads: EGNOS OS improves the GPS performances. Such enhancements depend on the specific GPS/EGNOS receiver, on the driving environment and on the antenna. In particular, the enhancements are less in case of dense tall buildings/foliage conditions and of the standard antenna (in both cases due to higher multipath effect). EGNOS CS/EDAS implemented in the LCS provides further improvements with respect to EGNOS OS. Additionally it provides a protection level, as a measure of the confidence on the quality of the position data from the GPS/EGNOS receiver (i.e. a confidence on the position calculation) and of the position guarantee. V. E2R OUTCOMES A. Extra-urban road operator/sat trials/business cases On the basis of the results of the technical analysis of the data collected during the trials, E2R has verified EGNOS enhanced performances in selected critical points of the present SAT stretches. E2R has proved that the extra-urban road operator interest in EGNOS relies on two main needs: The capability to distinguish two close/parallel roads of different networks, typically tolled and not-tolled stretches. The road operator needs to know whether the vehicle is on the motorway or on the secondary (not tolled) road, in situations where the two stretches are close and/or parallel. 18 As before detailed it is assumed that the two operators already use GPS 19 Service Levels SL0 and SL1, providing data access via TCP/IP connection 20 The platform implementing/providing the services 21 A SL providing data access through a SISNeT-like protocol is in plan 22 It should be considered that SAT is a Toll Charger presently using DSRC (Dedicated Short-Range Communications) for road charging Figure 8. E2R trials results in the case of SAT close/parallel roads

7 B. Urban road operator/rsm trials/business cases On the basis of the results of the technical analysis of the data collected during the trials, E2R has verified EGNOS enhanced performances in selected critical points and road in the city of Rome. The urban road operator interest towards EGNOS relies on the following main needs: The capability to distinguish close/parallel roads in various Limited Traffic Zone (LTZ) areas where different rules/pricing schemes are applied. The capability to distinguish roads in dense urban areas inside/outside the LTZ areas. The capability to monitor in real-time vehicles itineraries and stops, in line with permits. The capability to have a reliable positioning of urban regulated fleets. The next figure shows the E2R trials results in the case of RSM close/parallel roads. E2R has verified EGNOS enhanced performances in specific critical points of Rome stretches, on the basis of the technical analysis of the data collected during the trials. From the above plots, it is evident that for the selected critical points representing the occurrences identified by RSM as interesting for the operational assessment: EGNOS OS improves the GPS performances. Such enhancements depend on the specific GPS/EGNOS receiver, on the driving environment and on the antenna. In particular, the enhancements are less in case of dense tall buildings/foliage conditions and of the standard antenna (in both cases due to higher multipath effect). EGNOS CS/EDAS implemented in the LCS provides further improvements with respect to EGNOS OS. Additionally it provides a protection level, as a measure of the confidence on the quality of the position data from the GPS/EGNOS receiver (i.e. a confidence on the position calculation) and of the position guarantee. The enhancements and the quality of the protection level depend on the specific GPS/EGNOS receiver, on the driving environment and on the antenna. In particular, the enhancements and the quality are less in case of dense tall buildings/foliage conditions and of the standard antenna (in both cases due to higher multipath effect). As expected, the improvements due to the use of EGNOS OS and EGNOS CS/EDAS and the goodness of the protection levels obtained urban trials are less evident with respect to the extra-urban trials. This is due to the effects of multipath caused by narrow streets between high rise buildings, trees and dense foliage. 3.4 Results of technical data analyses The following tables summarize the results of the E2R technical data analysis. GPS/SBAS receiver 1 - Teseo GPS/SBAS receiver 1 - Teseo Right lane is inside the LTZ area left lane is out the LTZ area Figure 9. E2R trials results in the case of RSM close/parallel roads Table 1 Results of E2R technical data analyses

8 The following main indications can be outlined from the E2R trials: EGNOS OS improves the GPS performances. This behaviour is generally valid for all extra-urban and urban environments, for both the GPS/EGNOS receivers, and for both the antennas. However, it is observed that the enhancements depend on the specific GPS/EGNOS receiver, on the driving environment and on the antenna. In particular, the enhancements are less in case of dense tall buildings/foliage conditions and of the standard antenna EGNOS CS/EDAS implemented in the LCS provides further improvements wrt EGNOS OS. Additionally it provides a protection level, as a measure of the confidence on the quality of the position data from the GPS/EGNOS receiver (i.e. a confidence on the position calculation) and of the position guarantee The enhancements and the goodness of the protection level depend on the specific GPS/EGNOS receiver, on the driving environment and on the antenna. In particular, the enhancements and the goodness are less in case of dense tall buildings/foliage conditions and of the standard antenna (in both cases due to higher multipath effect). Thus, EGNOS OS generally enhances the position measured using GPS only in all extra-urban and urban environments, in the cases of both receivers. EGNOS CS/EDAS generally provides further enhancements, and also gives an indication of the quality of the position data received from the GPS. In particular it is important to notice that EGNOS OS and EGNOS CS/EDAS reduce the differences from the two receivers, and thus enable to mitigate the technological dependence of the position measurement. In fact, the positions obtained using GPS and GPS + EGNOS OS are the outcomes of the specific receiver functionalities. While, the processing done by the LCS, since it is done using the raw data, enables to have a higher control of the position determination. The above considerations are less evident, however still true also in case a standard antenna is used. It is important to stress that the EGNOS CS/EDAS performances are obtained by means of the LCS, implementing a Telespazio proprietary customization of the MOPS specifically for the road environments. VI. OUTLOOK In E2R two road operators SAT and RSM have had the opportunity to test the use of EGNOS OS and EGNOS CS/EDAS in some applications for extra-urban and urban mobility: road user charging, monitoring of traffic in limited access zones, tracking & tracing of regulated fleets. By means of extensive trials in various road environments (urban and extra-urban) representing real operation scenarios and business cases, E2R key findings are that: EGNOS OS generally enhances by three metres the position measured using GPS only in all extra-urban and urban environments. This result is still valid also in case of different receivers and antenna, though the type of antenna (professional amplified antenna versus standard patch antenna) has impacts on the position accuracy (measured with GPS and with GPS + EGNOS OS). EGNOS CS through EDAS generally provides further enhancements, and also gives an indication of the quality of the position data received from the GPS. It is important to stress that the EGNOS CS/EDAS performances are obtained by means of a specific implementation customizing the MOPS specifically for the road environments (in E2R LCS Telespazio s proprietary solution, has been used). On the basis of these findings, the two operators involved in E2R, SAT and RSM evaluated the added values of EGNOS with respect to GPS standalone. The benefits rely on enabling a more robust and reliable positioning. The improvement in accuracy and the qualification/confidence in the position are provided also in difficult urban environments, where GPS has limitations to cope with specific operational needs or due to environmental constraints (such as in the case of urban applications, those generated by toll building, dense fabric and foliage, typical of most European cities). This implies better performances in extra urban cases and enables also to generate economical benefits in the urban business cases considered in E2R. Thus, in E2R SAT and RSM have assessed that EGNOS today and Galileo in the future can: Enhance present applications and best practices already based on GPS Be adopted in present/future operations for which the use of the satellite navigation technology is in plan Develop new applications, supporting a more effective regulation of the traffic in city and suburbs areas and between urban and interurban roads (i.e. urban/extraurban interoperability). E2R outcomes have a more general validity: the assessment is an independent position concerning the use/value of EGNOS services in the perspective of Galileo for the considered road applications, elaborated on the basis of the results obtained from the performed analyses. E2R has shown that EGNOS provides services for road applications, and opens the market for Galileo. In fact, navigation solutions based on EGNOS, such as the LCS, are expected to be more robust with Galileo and in general with a multi-constellation GNSS, thanks to the availability of more satellites in view. E2R concepts and results, tailored on SAT and RSM specific business cases, are applicable to any other extraurban and urban operators, thus can be extended to other Italian/European road networks and cities.

9 VII. REFERENCES [1] EDAS, [2] GSA GNSS market report 2012, pdf