minutes of the sbas interoperability working group...
TRANSCRIPT
Minutes of the SBAS Interoperability Working Group (IWG) Meeting #25
Venue: SOKOS (St. Petersburg, Russia)Date / Time: June 25th to 27th 2013Participants: see list belowCo-Chairmen: Didier Flament (ESA) / Deane Bunce (FAA)Secretary: Felix Toran (ESA)
Meeting AgendaSee detailed meeting agenda annexed at the end of these MoM
List of participants
NAME COMPANY EMAIL ADDRESS
BUNCE Dean FAA [email protected]
BURNS Jason FAA [email protected]
ALEXANDER Kenneth FAA [email protected]
WALTER Todd Stanford [email protected]
BLANCH Juan Stanford [email protected]
LEJEUNE Roland MITRE Corporation [email protected]
Shripathi Venkatram SATISH ATM GAGAN [email protected]
Lingamaneni Sri Rama MOHANA RAO
GAGAN [email protected]
Ashok Kumar BHARDWAJ Civil Aviation India [email protected]
KARUTIN Sergey Russian Space Systems [email protected]
SHERENOV Alexander
Russian Space Systems
NIKITINA Margarita Russian Space System [email protected]
ISAEV Yury Russian Space System
BAKEEV Amir Russian Space Systems
KAPLEV SergeyFederal State Unitary Enterprise TSNIIMASH
OLEG Zavalishin LLC « NPPF Spectr » [email protected]
IWASHITA Nobuchika JCAB/Japan [email protected]
OCHIAI Shinichi JRANSA/Japan [email protected]
SAKAI Takeyasu ENRI/Japan [email protected]
BELLINGHAM Steve NAV CANADA [email protected]
FLAMENT Didier ESA [email protected]
HEIN Guenter ESA [email protected]
TORAN Felix ESA [email protected]
THOMAS David ESA [email protected]
BROCARD Daniel ESA [email protected]
SAMSON Jaron ESA [email protected]
JEANNOT Marc ESA [email protected]
LOPEZ Carlos ESA [email protected]
BULSA Gerard ESA [email protected]
DENIS Jean-Christophe ESA [email protected]
HOGREL Martine ESA [email protected]
MELINOTTE Jean-Manuel ESA [email protected]
LAM Juan Pedro ESA [email protected]
BOULANGER Cyrille ESA [email protected]
JIMENEZ David ESTEC [email protected] Stefan ESA/DLR [email protected]
SOLARI Giorgio ESA [email protected]
ERHARD Philippe ESA [email protected]
SALABERT Francisco EUROCONTROL [email protected]
CHATRE Eric EC [email protected]
ROTURIER Benoit Aviation Civile [email protected]
PUJOL Sylvain Aviation Civile [email protected]
ANTREICH Felix DLR [email protected]
LACARRA E. ESSP [email protected]
BILLOT Angelique ESSP [email protected]
CARRAZ Flavien ESSP [email protected]
ROLDAN Roberto ESSP [email protected]
SUARD Norbert CNES [email protected]
SECRETAN Hugues CNES [email protected]
MARGERY Michel CNES [email protected]
ZOBLER Dominique CNES [email protected]
List of input material
The list below presents all the input material to the SBAS IWG meeting #24. All the material mentioned below can be downloaded through the following URL:
ftp://epo-14r:[email protected]
1. EGNOS Program Update slides (EGNOS V2 Program update - IWG#24.ppt)2. WAAS status update (IWG 24 WAAS Status Brief 012313.ppt)3. Video Interview with NAC CEO David Karp.4. MSAS status debriefing slides (20130121-MSAS_IWG#24-rev2(Iws)-Mod.pptx)5. SDCM status presentation slides (SDCM 22 Jan 2013 EN .pptx)6. GAGAN status (IWG 24 - India.pdf)7. EGNOS LPV implementation in Europe (20130123_IWG24_LPV_Implementation-
ESSP.ppt)8. Open Service Guidelines debriefing slides (EGNOS open service guidelines for
receiver manufacturers IWG_v2.pptx)9. Protection of users out of Service Area slides (integrity out of SA - presentation
EC+ESA EPO.ppt)10. ESA R&D Program Update presentation slides (ESA EGEP Program -
Achievements 2012 and Extension program 2013-2015-final.ppt)11. SQM User Errors slides (SQM - presentation ESA EPO + DLR.ppt)
12. Characteristics / Models of GNSS signal distortions and anomalies (GPS block IIF, PRN25). (DLR_PRN25_GPS_IIF_anomalies_f.pptx)
13. L5 signal deformations presentation slides (SQM for DF WAAS_FAA update_Nov_2012_r7_IWGmodJan2013.pptx)
14. EGNOS Performance and Operational Implementation Status (ESSP-MEMO-8634_IWG24_EGNOS_Performance_01-00.ppt)
15. Ionospheric activities: Analysis results and planned activities (schlueter-IWG_SBAS_Toulouse-Iono.pptx)
16. Report on SBAS Iono Working Group (Walter_IWG24_SIWG_Update.pptx)17. Quick Facts: Worldwide SBAS (SBAS_Qfacts_01222013.pdf)18. SBAS Frequently Asked Questions DRAFT (SBAS FAQs DRAFT_20130108.doc)19. Global SBAS Status (SBAS Global Status Brief_20130123.ppt)20. EGNOS service introduction (EGNOS presentation IWG jan 2013.ppt)21. EGNOS Coverage Extension Plan and New Mission Requirements (EGNOS V3
MRD.ppt)22. DFMC Work Plan Update (DFMC Work Plan_US.ppt)23. DFMC Receiver Fallback Modes Progress Report
(DFMC_receiver_fallback_modes_IWG24_Jan_2013.pptx)24. DFMC Definition Document Outline (DFMC Outline_US_v5.ppt)25. RTCA debriefing (RTCA_SC-159_WG2_summary_IWG24_Jan2013.pptx)26. Summary Comparison SBAS L1/L5 ICD Models (ICD presentation EC+ESA
EPO.ppt).27. L1/L5 SBAS MOPS to Support Multiple Constellations (walter L1L5 SBAS MOPS
IWG24 Jan 2013.ppt)28. Invitation to the IWG#25 meeting (video.rar)29. GPS / GLONASS Multiconstellation SBAS Trial (IWG24_ENRI_MC-SBAS.ppt)
DAY 1
Welcome
M. Pircher (Director of CNES Toulouse Space Center) welcomed participants to CNES and wished a fruitful meeting. D. Flament and D. Bunce introduced the IWG meeting.
Approval of agenda
The agenda was approved (see annex).
EGNOS Status (Presented by D. Flament)
The architecture of EGNOS is presented, followed by the release plan of EGNOS, from v2.2-ext (the first certifiable release of EGNOS) until future V2.4.2. The current version in operation is V2.3.1i, with important improvements in term of iono robustness. V2.3.2 will be qualified in June 2013 and entering operations in August 2013. Following release will be V2.4.1M, to be qualified in June 2014. It will include mission evolutions as MOPS D compliance, LPV200 service, plus resolution of obsolescence issues and other important features. Four RIMS are still to be deployed (up to a total of 41). Part of them are planned to be deployed through V2.3.2 (see slides [1]).
The CDR of V2.3.2 has been passed, and V2.4.1M CDR is under preparation.
The Luch 5B satellite (SDCM) is collocated with EGNOS GEO PRN 120. This possible interference issue is under discussion.
A comparison of performances between version 2.2 and 2.3.1i for a same day shows a clear improvement with v2.3.1i. Another comparison using a known day with an underperformance shows the important performance improvements obtained from v2.3.2. Performances observed today in the system are nominal.
In terms of GEOs, ARTEMIS is used for test. ASTRA-4B acceptance is expected by mid 2013, to be used for test and then for operations in 2014.
The coming two years are transition ones, towards a new framework for 2014-2020. A Phase B for extension of EGNOS L1 service over Africa (South Africa and ASECNA) is pending EC decision.
It is clarified that, for the new RIMS (to resolve obsolescence issues), it is still under discussion if they will be based on new or existing hardware.
It is clarified that ESA is planning to collect data in Africa during solar peak, through ESA activity called MONITOR. In addition, a CNES activity will deploy stations in Africa to feed ESA with further data.
See slides [1] for more details.
WAAS/GPS Status presentation (D. Bunce)
38 reference stations (no plan to add more in the short term).Currently in phase IV, dual frequency L1/L5 operations (2014-2018). Transition from L2 to L5 will be completed through this phase. The single frequency SBAS service will be maintained.
Four releases throughout phase III, including improvements in iono robustness.
Three GEOs are in use currently: CRW, CRE and AMR. GEO 5 is expected to be in the system by 2015, GEO 6 in 2018 and GEO 7 in 2019. LPV coverage includes US, Canada and Mexico. Performance has improved thanks to implementation of Kriging method.
It is considered by the group that a risk exists on the timely deployment of Block IIF satellites. In order to validate the system, WAAS needs 18 satellites available. In case of delay in GPS constellation deployment, the group overall opinion is that the MOPS development should not be delayed as a consequence.
Simulations show that transition from L2 to L5 should be done when there are 24+ satellites. Doing it before would mean a degradation of performance.
Next generation receiver (G-III) is under development (to be completed in 2013). WAAS safety computer (supporting dual frequency upgrades and adding significant new capabilities) initial production will take place in 2013.
In terms of approaches, near 3500 LPV approaches published. Outreach initiatives continue to grow, with NOrther Air Cargo, Bell helicopters, CapeAir, Care Flight and FAA citations, Horizon, Express Jet, etc.
In terms of extension to South America, discussions are ongoing, but nothing has been formalized at this time.
A video interview with Northern Air Cargo CEO was projected, showing Boeing fleet equipped with WAAS and reporting on the different benefits including safety, fuel saving, etc.
See slides [2] and video [3] for more details.
MSAS Status debriefing (Presented by Nobuchika Iwashita)
Basically, there is no change in status of MSAS since last IWG meeting. 2014 is a decision making year concerning the future replacement of MTSAT satellites.
MSAS is used in regional air carriers, fire fighting, medical helicopters, etc.
QZSS status is also reported. It is managed from a different organization than MSAS. It is still to be concluded (by end of March 2013) whether QZSS will provide or not an SBAS service.
See slides [4] for more details.
SDCM / GLONASS Status debriefing (Presented by S. Rybkin)
The system is under development. There are international activities, including possible areas of cooperation with WAAS and MSAS, and participation to IWG.Full coverage with GPS L1 only augmentation is planned in 2015 and with dual frequency in 2018. The level of service will be LPV-200.
Certification process will start with the coverage of central area of Russia. By 2018, the plan is to have L1/L5 GPS and L1/L3 GLONASS signals used. The target is LPV-200 service.
Three L1 GEOs, one L1/L3/L5 GEO and SISNeT are the broadcast means. The system will have 40 reference stations, with up to 7 along the Russian borders.
Luch 5A and 5B are operational. Luch 5V expected to be operational in 2014. Performance maps show some degradation in the South, due to the lack of stations.
SDCM is cooperating with EGNOS, with an SBAS efficiency study for Eastern Europe and market development activities in the context of EC 7th Framework Program.
The concept of dynamic PRN mask will be implemented during the second part of the project.
See slides [5] for more details.
GAGAN Status Debriefing
Since December 2011 GAGAN SIS is available on PRN127 for testing and evaluation. The ground segment of GAGAN system architecture is in place with 15 Indian Reference Stations (INRES), 2 Indian Master Control Centers (INMCC) and 3 Indian Land Uplink Stations (INLUS).
A communication network comprising of four circuits, using terrestrial / space media is being established for GAGAN to ensure 99.999% availability. Final System Acceptance Testing was successfully completed on 16th and 17th July 2012.
GAGAN system functions in the equatorial ionosphere region wherein the spatial and temporal variability is high and therefore India has developed necessary Ionosphere model specifically for this region. IGM-MLDF (Ionospheric Grid Model – Multi Layered Data Fusion) model has been implemented for GAGAN system.
The Space segment of GAGAN system comprises of 2 operational GEOs ( GSAT-8/PRN 127, GSAT-10/PRN 128) and one GEO as in-orbit spare (GSAT-15), to belaunched in 2015.
GSAT-8 satellite (PRN 127) is operational for non-safety critical applications sinceDecember 2011. GSAT-10 (PRN 128) is undergoing system integration and itsservices will be available after February 2013.
The FSAT test results and thereafter GAGAN system performance has been continuouslymonitored and data is collected for various analysis including HMI. Sample results are shown todemonstrate the GAGAN system performance parameters are within the specified limits fornominal day operations.
MITRE is supporting the GAGAN certification activities. GAGAN will be certified for APV-I.
Since GAGAN fills the coverage gap between EGNOS and MSAS, India urges IWG to provide assistance to detect any interoperability issue, especially with EGNOS.
For more details, see slides [6].
GAGAN is in its final operational phase. GAGAN covers 70% of Indian territory due to constraints for siting Reference stations outside its homeland, yet has extension capabilities to other regions, as Africa, Australia, etc.
LPV Implementation Status (E. Lacarra)
The different EGNOS services are presented (Open Service, Safety of Life and EDAS).
A SoL Service Definition Diocument was published on March 2011. EGNOS service notices are generated by the operator. A contingency communication plan has been agreed with EUROCONTROL, DSNA and EASA.
An example of a SoL service degradation affecting some airports at the North of Germany and the NOTAM proposals sent was shown.
EGNOS Working Agreements (EWAs) with DSNA, Skyguide, Guernsey Airport, DFS, ENAV, NAATS, Austrocontrol and AENA signed.
F. Salabert presents the EUROCONTROL One Sky online PBN approach map tool. There are 1.536 airports in Europe. Today there are 49 implemented LPV approaches. The plan for the next 5 years is to arrive (in 2018) to 377 published procedures.
See slides [7] for more details.
Open Service Guidelines Document (D. Jimenez, ESA)
Open service guidelines for receiver manufacturers have been developed by ESA, in coordination with EC. Open service focuses on accuracy and availability, so the goal is to improve those performance parameters and simplify as much as possible the algorithms with respect to the DO 299D, which is focusing on SoL.
Four axes of improvement have been studied: combination of subsets of corrections, combination of corrected and uncorrected satellites, new iono interpolation method and extension of the correction update rate.
The Open Service guidelines document report is available to IWG members interested.
E. Chatre explains that a number of receiver manufacturers which may benefit from these guidelines have been identified by European Commission. A list of guidelines will be elaborated, and this document prepared by ESA has been a key contribution. Today there is
an SDD document for Open Service that should be updated in the future to include receiver guidelines.
See slides [8] for more details.
LPV200 Requirements Interpretation (E. Chatre / F. Salabert)
E. Chatre introduces the topic. ICAO guidance material on LPV-200 has led to some ambiguous interpretations for the different SBAS systems. Stanford University produced a paper on interpretation of LPV200 requirements.
Additional work is found needed to arrive to clarify the interpretation of the guidance material. EUROCONTROL has performed flight testing to support this. FAA is also performing simulations. Those simulations will feed the next NSP meeting for conclusion on the topic.
When the outcome of FAA simulations is available, a paper will be prepared as input to NSP to capture the result.
SBAS Continuity Way-Forward and Harmonization (F. Salabert, EUROCONTROL)
Following iterations at IWG level since 2010, an ICAO Working Paper was prepared and presented to NSP by mid 2012. Three comments were received and have been discussed at IWG #24:
“Number of available samples” need to be defined more clearly. Considered that an available sample is when the PL can be computed and PL<AL.
Minimum period to compute continuity (so that the agreed method can be used to show compliance to continuity requirement) is discussed. The working group is not able to define a duration, but it is considered reasonable that it must be longer than one month.
It is clarified that the step of the sliding window is one second.
The receiver implementations are based on instantaneous receiver switching between both GEOs to avoid having a continuity event.
Reference to MT63 removed.
Concerning NOTAM, the correct reference to ICAO material has been introduced, as requested by NSP.
The paper will be edited and circulated for final comments.
ACTION A1: F. Salabert to edit the Continuity Working Paper according to discussions and circulate it to the group for final comments.
Protection of users out of the service área (E. Chatre / D. Brocard)
D. Brocard sets the context by presenting (see [9]) how users are protected in EGNOS V2 and V3.
In EGNOS V2, the use of MT27 ensures protection out of ECAC.
EGNOS V3 is moving towards using MT28. This provides protection inside ECAC. Yet integrity for out of ECAC (indeed within the GEO footprint) may not be guaranteed unless specific protection is implemented.
The questions are:
Does EGNOS need for SBAS to protect (by themselves) users out of service area for PA and NPA operations?
In case of having to protect users out of service area, how to minimise extra system complexity and performance regression inside service area?
Eric Chatre presents the EU point of view (see [9]):
For PA, only published procedures can be flown (so only PA procedures within the service area will be selectable by aircraft avionics). Therefore, no need for the SBAS to protect users out of the service area.
For en-route to NPA, there is no implicit mechanism to protect users out of service area. Therefore, such protection needs to be provided by the SBAS system.
The EGNOS view on protection of users out of SA is shared by WAAS and the group. WAAS is not using a concept of service area, since they use MT28.
WAAS has implemented an “a priori” approach for MT28 to demonstrate protection of the users out of service area (CONUS), which is certified. There is a technical commitment of protection beyond CONUS for WAAS (based on MT28) , even though it does not have legal status and all relevant liabilities are disclaimed outside the service area as they will have to be borne completely by the country concerned.
SDCM informs that there are no plans defined to implement MT28 in their system.
ESA R&D Program Update (D. Thomas)
D. Thomas introduces EGNOS V3 and the expected performances in the future, towards a global coverage through interoperability with other SBAS systems. Phase A activities were concluded (two parallel consortia). Two parallel phase B activities with two consortia have been procured, with an SRR milestone expected by mid 2013 and PDR in 2014.
EGNOS V3 is accompanied by several experimentation activities (test beds): High integrity test bed, ARCTIC test bed, Multiconstellation Regional System test bed. Several technology predevelopments are ongoing. An experiment with GATE (helicopter trials) has been successfully performed.
See [10] for more details.
SQM User Error (F. Antreich / D. Brocard )
D. Brocard introduces the context. The preliminary analysis presented at IWG#22 is recalled. That analysis was preliminary and had some limitations which are intended to be covered through the following EPO/DLR activity .
F. Antreich presents the results of the analysis performed by DLR. A 30m dish antenna has been used by DLR.
First nominal analog and digital distortions have been measured on one SV block IIF for both L1 and L5 signals.
Then models have been tuned in order to match the observed distortions. Some further work remains however to be performed especially on L5 model.
Finally impact of distortions on on user error was (roughly) estimated as a function of the differential design between User and System receivers characteristics.
Way forward:
Consolidate distortions characteristics by measuring on more SVs Refine the characterisation of signal distortions (versus time, SV ageing effect,
block, constellation –e.g. GALILEO). Consolidate derivation from signal model to user errors Assess system performance impacts Derive ICD+receiver MOPS recommendations
See [11] and [12] for more details.
L5 Signal Deformation (T. Walter)
The slides show a proposal to be used as a starting point, to be further discussed with RTCA.
See [13] for more details.
SBAS Ionosphere: EGNOS 2012 observations (A. Billot)
EGNOS performance improvements thanks to V2.3.1i against strong iono are shown, for days with difficult ionospheric conditions.
The observed impact of solar activity in the North of ECAC in December 2012 is shown. V2.3.1i has shown robustness against those events.
See slides [14].
SBAS Ionosphere: Analysis results and planned activities (S. Schlueter)
Some examples of iono impact on EGNOS availability are shown, including 8-9 october 2012 and 5th of december (underperformance on the North of ECAC).
For the case of 5th of December 2012, the iono was really calm. The cause was a regional effect. V2.3.2 release of EGNOS will implement iono threshold tuning, allowing to make the system robust against such kind of events.
Data and tools used for iono qualification and event analysis are shown (see slides [15]).
The ICASES activity is presented, aiming at defining high level and unambiguous ionospheric condition indicator. The selected indicator is the AATR (Along Arc TEC Rate). The different maximum values for AATR in different regions are shown. These results have fed the EGNOS V3 Mission Requirements Document (MRD).
The ionospheric scenarios are being upgraded. Under EGEP activities, some experiments are planned as SBAS in the polar region (Arctic test bed), MONITOR activities in Africa.
A CNES project will deploy a number of scintillation receivers in Africa to collect raw data and support MONITOR project.
It is considered important to share between SBAS systems on their way of iono qualification, data used, thresholds employed, etc. The way iono qualification is performed in EGNOS is explained overall.
See [15] for more details.
SBAS Ionosphere: IONO Working Group (T. Walter)
Total of 19 meetings held to the date. Two major papers have been produced, the first one on ionospheric research issues for SBAS (2003) and “Effect of ionospheric scintillation on GNSS” (2010).
The current topics of discussion are monitoring networks, identification of iono events, effects of recent storms, ionosphere modelling, proposed MOPS changes for scintillation and progression of solar cycle 24.
Solar cycle 24 is expected to have much less impact than the previous one.
The next meeting of this subgroup of IWG will meet in Bath, UK, in July 2013. The iono WG will continue to meet once or twice a year.
Since June 2012, no major iono events have been observerd over CONUS. The most significant event happened on September 30th 2012, having impact over Alaska and Canada.
It is clarified that the IGPs over the South of Mexico are still not active, and this can be seen in the performance maps.
See [16] for more details.
DAY 2
Global SBAS presentation / fact sheets (J. Burns)
The update of the global SBAS fact sheet is presented, promoting SBAS benefits, interoperability, evolution, etc. The updated Frequently Asked Questions document is also presented.
J. Burns will complement the fact sheet by including the acceptance and certification planned dates for SDCM.
Concerning the issues related to transition between SBAS systems, the message is found negative for a big public. It will be corrected and made more positive.
It is agreed to reflect in the fact sheet that GAGAN and SDCM are coming to scene with a single frequency service (prior to WAAS and EGNOS dual frequency).
See [17], [18] and [19] for more details.
It is agreed to send comments to J. Burns on the different sections of the documents before IWG #25
ACTION A2: IWG members to send comments on the SBAS FAQ and SBAS global fact sheet to J. Burns (deadline: March 2013)
ACTION A3: J. Burns to update the fact sheet according to discussions held at IWG#24 and comments received (deadline IWG #25)
EGNOS Service Introduction Status (C. Villie)
The key EGNOS program milestones are presented (see [20] for more details). For each review, there is KO of the development phase, followed by qualification and finally deployment. In the case there are safety critical changes, a safety case is presented to the regulator and, once approved, the deployment takes place.
It is clarified that the performances shown in the Service Definition Document (SDD) are conservative.
EGNOS Coverage Extension Plan and New Mission Requirements (E. Chatre)
See [21] for more details. The top level document driving the mission is the HLD. A SoL expert group supports the update of that document. In the short-term, this group is targeting the early use of Galileo Open Service. In the medium term, the group is focusing on evolutions of EGNOS SoL (dual frequency and dual constellation).
EGNOS V3 mission includes a legacy service (L1 only), dual frequency (GPS L1/L5 augmentation) and dual frequency-dual constellation (GPS and Galileo dual frequency augmentation). It includes also Cat I precision approach down to autoland, plus maritime service, open service and time service.
A first issue of the EGNOS MRD V3 has been approved by the MRD CCB . It will be sent formally to ESA, with the agreement of European Commission to continue EGNOS V3 activities based on this document.
In terms of coverage, first priority is EU27, then accessing countries and then ENP countries. Compatibility with extension to Africa is also specified.
The baseline broadcast means is based on GEO. Alternative broadcast means are being studied under ESA R&D activities, and it is too early to set mission requirements at this stage.
SBAS DFMC Definition and Framework (J. Burns, R. Lejeune)
Three presentations guided the discussion (see [22], [23] and [24] for more details).
A work plan update [22] is presented, following the first draft presented at IWG #23. Tasks include operational concept, system requirements, interface definition and writing the definition document.
Transition between GEOs to enable SBAS interoperability is included. A white paper is in development on this topic.
Reversionary modes are also studied. There are contributions from Eurocontrol, MITRE and EC.
A Definition Document has been initiated and will be maintained. IWG is called to contribute.Following discussion, it is agreed that this work plan must be synchronized with the work plans at ICAO and RTCA levels.
Concerning the development of MOPS for DFMC, the first step for RTCA is to develop MOPS for GPS L1/L5 SBAS augmentation. In a second step, Galileo E1/E5 will be added.
The use of RAIM as a backup of SBAS is included. ARAIM may be included in the future, once a complete an stable definition is available.
Tolerance to frequency loss (i.e. possibility for an SBAS to augment L5 only) is left TBD.
Fallback modes include three modes in which integrity is provided by RAIM.
The augmentation for L1 will come from SBAS L1 GEO lane. The agumentation for dual frequency users will come from SBAS L5 lane. In case of having tolerance to frequency loss (which is currently TBD, and not considered in the US), the augmentation of GPS L5 will obviously come from the GEO L5 lane.
It is clarified that RAIM must be used as a backup of SBAS for NPA. The augmentation of GPS L5 only will be considered in the MOPS standards, so that the receivers are prepared to use it. If this service is not provided by an SBAS system, in case of losing SBAS L1, the receiver will revert to RAIM.
The outline of the definition document is presented. IWG members are requested to provide feedback on the presented outline. The drafting of sections will begin.
SDCM and GAGAN are invited to provide a point of contact for the contribution to the review of the document in between IWG meetings.
ACTION A4: IWG members to send comments on the DFMC definition document and draft text to J. Burns (deadline: April 2013).
ACTION A5: Develop a paper for ICAO NSP outlining the DFMC work plan, to be presented at the next RTCA SC-159 and EUROCAE WG-62 meeting (June 2013) in order to synchronise workplans. (J. Burns leads with the support of IWG members). Deadline: March 2013 RTCA SC-159 meeting.
ACTION A6: All SBAS providers to identify point of contact for DFMC definition document contribution and send it to J. Burns. Deadline: mid February 2013.
ACTION A7: ESA to propose a date for a Webex teleconference for DFMC intermediate discussion in preparation for NSP meeting. Deadline: February 2013.
ICAO NSP Status (E. Chatre)
Navigation was not a the very center of the conference, but GNSS capabilities are a stepping stone for the features to be improved in the future. Multiconstellation has been recognized as the norm for the near future. The benefits are recognised. The technical challenges are noted. Conclusion is that ICAO has to work to introduce multiconstellation solutions in the future, through a workplan. Next NSP meeting will be in March 2013.
NSP also started discussions about the possibility to standardize regional systems as Beidou, something not compatible with SBAS standards.
EUROCAE WG-62 Status and Proposed Future Efforts (S. Pujol)
WG-62 is preparing a CONOPS document for multiconstellation receivers, which is found in line with the DFMC discussion held at IWG #24.
WG-62 also contributes to the development of future GPS/GALILEO/SBAS MOPS.
The Galileo MOPS will be addressed in the next meeting of WG-62. A slot will be added to present the DFMC workplan from IWG, in order to synchronise with the WG-62 workplan.
RTCA SC-159 Status and Proposed Future Efforts (R. Lejeune)
Last meeting was held in October 2012. Status updates were presented on WAAS, EGNOS, GALILEO. Change 1 to DO-299D was discussed. It is planned to be approved in February 2013.
SARPS/MOPS consistency (including MT 9/17 issue) was discussed. DFMC issues were also discussed.
Russian Ministry has issued a mandate for GLONASS or GPS/GLONASS equipage: foreign manufactured aircraft must be equipped by 2017. Airframe manufactured showed concerns to meet that deadline. WG2 agreed to outline the information that would be necessary if MOPS development is requested.
Next WG2 meeting will be held on the week of March 11th, and the next one temptatively on the week of October 7th.
See [25] for more details.
SBAS L1/L5 SIS ICD (European activity results) (D. Brocard)
Two relevant SBAS L1/L5 candidate ICD’s have been identified. One is based on current SBAS standard coupled with a dynamic mask concept at system + User (ICD1), while the other (ICD2) is based on a new DFRE message type (capable of augmenting 91 satellites, no FC, single message with SV corrections & rates, covariance, DFREi, etc.)
A comparison of the two approaches is shown, in order for the group to take a position on the way forward.
Several aspects are compared:
Performance. With lower number of satellites, ICD1 works better. However, when number of satellites increases, ICD2 shows better results. Overall, with 1-2 constellations ICD1 works better. For 3-4 constellations, ICD 2 performs better.
GNSS specifications dependence : ICD 2 is more sensitive than ICD1.
Robustness. The capability of ICD to cope with unexpected situations as message loss. The border effect impact has been assessed. It has a slight impact on ICD1, while it is higher in ICD2.
Simplicity for user equipment implementation. ICD1 is heavy to implement. Easier for ICD2.
Expandability. The performance impact will come from GIVE degradation on L5 compared with L1, not from ICDs.
As conclusion of the comparative, none of both models has only benefits. ICD 1 is better than ICD 2 for some criteria, while ICD2 is better than ICD1 for others. Both ICDs are found relevant for DFMC standard in so far service level performances can be met (e.g. LPV200 with DF simple constellation, Cat1 autoland with DF dual constellation).
A proposed alternative to ICD1 is proposed, based on broadcasting as many MT6 as necessary (see slides for more details). An alternative is proposed also for ICD 2 (see slides for details). By comparing both, ICD 1 alternative seems to offer the best results.
Way forward is now to work with a single document and work together on it, instead of working in two parallel ICDs. This will be done (as discussed earlier) in the frame of the DFMC definition document. In the frame of EC activities, this document can be maintained in configuration.
As way forward, it is proposed to orient the focus of IWG work towards the technical issues and workplans managed by this group. The programmatic debriefings should take a secondary role.
See [26] for more details.
SBAS L1/L5 SIS ICD (T. Walter)
The presentation provides more details on the so-called ICD_2 in the precedent section. The approach consists on using a new MT6-like message, and removing fast corrections. The proposed message also includes MT28 parameters. This new message is not used to provide any critical information. The SBAS almanac message format is also presented (two satellites per message). In the event of an alert, the integrity alert replaces the four messages that would have gone in those slots. Proposed message time outs are presented (see slides). The proposed structure is very similar to that of existing L1-only MOPS.
See slides [27] for details.
It is agreed to place the two ICD proposals together with justifications and possible enhancements in an annex of the DFMC definition document.
ACTION A8: J. Burns to include an annex with the two ICD proposals in the DFMC definition document
Review of meeting objectives and actual achievements
Actions from previous meeting are reviewed. There were three actions raised, which are closed.
Summary and agreement on new action items
F. Toran recalls the actions captured during the IWG#24 meeting (see table below). Those actions are reviewed and agreed.
Future meeting schedule and location
M. Nikitina presents the location of the next IWG #25 (see video [28]). It will take place in Saint Petersburg, 25-27 June 2013 in Sokos Hotel Palace Bridge. A room reservation form is provided, and it is requested to be returned before 25th May 2013. A visit to the Radio Astronomical Observatory of Russian Academy of Science will be organized. Reservation forms and formal invitations will be sent after this meeting.
List of Actions
Ref. Action Actionee DeadlineA1 Edit the continuity computation method
working paper according to discussions and circulate it to the group for final comments.
F. Salabert February 2013
A2 IWG members to send comments on the SBAS FAQ and SBAS global fact sheet to J. Burns (deadline: March 2013)
All March 2013
A3 Update the fact sheet according to discussions held at IWG#24 and comments received (deadline IWG #25)
J. Burns IWG #25
A4 Send comments on the DFMC definition document and draft text to J. Burns
All April 2013
A5 Develop a paper for ICAO NSP outlining the DFMC work plan, to be presented at the next RTCA SC-159 and EUROCAE WG-62 meeting (June 2013) in order to synchronise workplans.
J. Burns leads with support of IWG PoC
March 2013 RTCA SC-159 meeting.
A6 All SBAS providers to identify point of contact for DFMC definition document contribution and send it to J. Burns.
All Mid Februrary 2013
A7 Propose a date for a Webex teleconference for DFMC intermediate discussion in preparation for NSP meeting.
ESA February 2013
A8 Iinclude an annex with the two ICD proposals in the DFMC definition document
J. Burns IWG#25
ANNEX A: DETAILED MEETING AGENDA
Day 1- 23 rd of January
09:00 – 09:40 Welcome
Welcome to French Space Agency - Toulouse Space Center Director – M. Pircher
Welcome to SBAS Technical IWG meeting 24 Co-Chairs Introduction of participants All Administrative Information Co-Chairs Review and Agree on Agenda All
Objective 1 Harmonize SBAS Modernization Plans
09:40 – 10:50 SBAS Program Status & Modernization Plans (1/2)
WAAS/GPS FAA EGNOS ESA MSAS JCAB SDCM RSS
10:50 – 11:00 Coffee Break
11:00 – 11:30 SBAS Program Status & Modernization Plans (2/2)
GAGAN AAI LPV implementation status ESSP
Objective 3 Harmonize technical improvements from operation and users feedback
11:30 – 12:45
EGNOS OS guidelines document (update) ESA LPV200 Requirements Interpretation EC/Eurocontrol/FAA SBAS Continuity Way-Forward and Harmonization EUROCONTROL Protection of users out the service area EC/ESA
12:45 – 14:00 Lunch
Objective 4 R&D cooperation on key SBAS technologies (continued)
14:00 – 17:00 ESA R&D program update ESA SQM User Error ESA/DLR L5 Signal Deformations (update) Stanford
17:00 – 17:10 Coffee Break
17:10 – 18:00 SBAS & Ionosphere
o EGNOS 2012 observations ESSPo Analysis results and planned activities ESAo IONO Working Group Stanford
Day 2- 24 th of January
Objective 5 Support joint SBAS promotion
09:00 – 09:30
Global SBAS presentation / fact sheets FAA EGNOS Service Introduction status EC EGNOS Coverage Extension Plan and new mission requirements EC
Objective 2 Forum for discussion on SBAS Standards
09:30 – 11:00
SBAS DFMC Definition and Framework FAA Group Discussion All
11:00 – 11:15 Coffee Break
11:15 – 12:00
ICAO NSP status EC Eurocae WG-62 Status and proposed Future efforts EC
12:00 – 13:30 Lunch
Objective 2 Forum for discussion on SBAS Standards
13:30 – 15:30 Update on SBAS/GNSS Standards
RTCA SC-159 Status and proposed Future efforts MITRE/Stanford SBAS L1/L5 SIS ICD (European activity results) ESA SBAS L1/L5 SIS ICD Stanford
15:30 – 16:30 Other Business
SBAS IWG (SBAS for non-Aviation Users) All Review of Meeting Objectives and actual achievements All Summary and agreement on new Action Items All Future meeting schedule and location All
16:30 End of Day 2 meeting
Day 3- 25 th of January
9:00 – 10:30 Visit to the EGNOS PACF facility All
11:00 – 12:30 Visit to the ATV Control Center All
ANNEX B: IWG-24 GROUP PHOTO