Minutes of the SBAS Interoperability Working Group (IWG) Meeting #25
Venue: SOKOS (St. Petersburg, Russia)
Date / Time: June 25th to 27th 2013
Participants: see list below
Co-Chairmen: Didier Flament (ESA) / Deane Bunce (FAA)
Secretary: Felix Toran (ESA)
Meeting Agenda
See detailed meeting agenda annexed at the end of these MoM
List of participants
NAME
COMPANY
EMAIL ADDRESS
BUNCE Dean
FAA
deane.bunce@faa.gov
BURNS Jason
FAA
Jason.burns@faa.gov
ALEXANDER
Kenneth
FAA
ken.alexander@faa.gov
WALTER Todd
Stanford
twalter@stanford.edu
BLANCH Juan
Stanford
blanch@stanford.edu
LEJEUNE Roland
MITRE Corporation
rlejeune@mitre.org
ATM GAGAN
svsatish@AAI.AERO
GAGAN
mohan_lsr@rediffmail.com
Civil Aviation India
Akbhardwaj.dgca@nic.in
Shripathi Venkatram
SATISH
Lingamaneni Sri
Rama MOHANA
RAO
Ashok Kumar
BHARDWAJ
SHERENOV
Alexander
Russian Space
Systems
Russian Space
Systems
NIKITINA Margarita
Russian Space System
ISAEV Yury
Russian Space System
KARUTIN Sergey
BAKEEV Amir
KAPLEV Sergey
Russian Space
Systems
Federal State Unitary
Enterprise
TSNIIMASH
sergey.karutin@rniikp.ru
nikrit@inbox.ru
OLEG Zavalishin
LLC « NPPF Spectr »
avia@nppf-spectr.ru
IWASHITA
Nobuchika
JCAB/Japan
iwashita-n298@mlit.go.jp
OCHIAI Shinichi
JRANSA/Japan
ochiai-sh@jransa.or.jp
SAKAI Takeyasu
ENRI/Japan
sakai@enri.go.jp
BELLINGHAM Steve
NAV CANADA
bellist@navcanada.ca
FLAMENT Didier
ESA
didier.flament@esa.int
HEIN Guenter
ESA
Guenter.hein@esa.int
TORAN Felix
ESA
Felix.toran@esa.int
THOMAS David
ESA
David.thomas@esa.int
BROCARD Daniel
ESA
Daniel.Brocard@esa.int
SAMSON Jaron
ESA
Jaron.samson@esa.int
JEANNOT Marc
ESA
Marc.jeannot@esa.int
LOPEZ Carlos
ESA
Carlos.lopez@esa.int
BULSA Gerard
ESA
Gerard.bulsa@esa.int
DENIS JeanChristophe
ESA
Jean-christophe.denis@esa.int
HOGREL Martine
ESA
Martine.hogrel@esa.int
MELINOTTE JeanManuel
ESA
Jean.manuel.melinotte@esa.int
LAM Juan Pedro
ESA
Juan.pedro.lam@esa.int
BOULANGER
Cyrille
ESA
Cyrille.boulanger@esa.int
JIMENEZ David
ESTEC
David.jimenez@esa.int
SCHLUETER Stefan
ESA/DLR
Stefan.Schlueter@esa.int
SOLARI Giorgio
ESA
Giorgio.solari@esa.int
ERHARD Philippe
ESA
Philippe.erhard@esa.int
SALABERT
Francisco
EUROCONTROL
francisco.salabert@eurocontrol.int
CHATRE Eric
EC
Eric.CHATRE@ec.europa.eu
ROTURIER Benoit
Aviation Civile
benoit.roturier@aviation-civile.gouv.fr
PUJOL Sylvain
Aviation Civile
Sylvain.pujol@aviation-civile.gouv.fr
ANTREICH Felix
DLR
Felix.antreich@dlr.de
LACARRA E.
ESSP
Elisabet.lacarra@essp-sas.eu
BILLOT Angelique
ESSP
angeline.billot@essp.cnes.fr
CARRAZ Flavien
ESSP
Flavien.carraz@essp.cnes.fr
ROLDAN Roberto
ESSP
rroldan@e-externas.aena.es
SUARD Norbert
CNES
Norbert.Suard@cnes.fr
SECRETAN Hugues
CNES
Hugues.secretan@cnes.fr
MARGERY Michel
CNES
Michel.margery@cnes.fr
ZOBLER Dominique
CNES
Dominique.zobler@cnes.fr
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:ePo!04!iwG@ftp.esrin.esa.int
1.
2.
3.
4.
5.
6.
7.
EGNOS Program Update slides (EGNOS V2 Program update - IWG#24.ppt)
WAAS status update (IWG 24 WAAS Status Brief 012313.ppt)
Video Interview with NAC CEO David Karp.
MSAS status debriefing slides (20130121-MSAS_IWG#24-rev2(Iws)-Mod.pptx)
SDCM status presentation slides (SDCM 22 Jan 2013 EN .pptx)
GAGAN status (IWG 24 - India.pdf)
EGNOS LPV implementation in Europe (20130123_IWG24_LPV_ImplementationESSP.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-MEMO8634_IWG24_EGNOS_Performance_01-00.ppt)
15. Ionospheric activities: Analysis results and planned activities (schlueterIWG_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 v2.2ext (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 ( GSAT8/PRN 127, GSAT-10/PRN 128) and one GEO as in-orbit spare (GSAT-15), to be
launched in 2015.
GSAT-8 satellite (PRN 127) is operational for non-safety critical applications since
December 2011. GSAT-10 (PRN 128) is undergoing system integration and its
services will be available after February 2013.
The FSAT test results and thereafter GAGAN system performance has been continuously
monitored and data is collected for various analysis including HMI. Sample results are shown to
demonstrate the GAGAN system performance parameters are within the specified limits for
nominal 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 Document 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 beenidentified. 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.
A1
A2
A3
A4
A5
A6
A7
Action
Edit the continuity computation method
working paper according to discussions
and circulate it to the group for final
comments.
IWG members to send comments on the
SBAS FAQ and SBAS global fact sheet to
J. Burns (deadline: March 2013)
Update the fact sheet according to
discussions held at IWG#24 and
comments received (deadline IWG #25)
Send comments on the DFMC definition
document and draft text to J. Burns
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.
All SBAS providers to identify point of
contact for DFMC definition document
contribution and send it to J. Burns.
Propose
a
date for
a Webex
Actionee
F. Salabert
Deadline
February 2013
All
March 2013
J. Burns
IWG #25
All
April 2013
J. Burns leads March 2013 RTCA
with support of SC-159 meeting.
IWG PoC
All
Mid Februrary 2013
ESA
February 2013
A8
teleconference for DFMC intermediate
discussion in preparation for NSP
meeting.
Iinclude an annex with the two ICD J. Burns
proposals in the DFMC definition
document
IWG#25
ANNEX A: DETAILED MEETING AGENDA
Day 1- 23rd of January
09:00 – 09:40





Objective 1
Welcome
Welcome to French Space Agency - Toulouse Space Center
Welcome to SBAS Technical IWG meeting 24
Introduction of participants
Administrative Information
Review and Agree on Agenda
Director – M. Pircher
Co-Chairs
All
Co-Chairs
All
Harmonize SBAS Modernization Plans
09:40 – 10:50 SBAS Program Status & Modernization Plans (1/2)




10:50 – 11:00
WAAS/GPS
EGNOS
MSAS
SDCM
FAA
ESA
JCAB
RSS
Coffee Break
11:00 – 11:30 SBAS Program Status & Modernization Plans (2/2)


GAGAN
LPV implementation status
AAI
ESSP
Objective 3
feedback
Harmonize technical improvements from operation and users
11:30 – 12:45




EGNOS OS guidelines document (update)
LPV200 Requirements Interpretation
SBAS Continuity Way-Forward and Harmonization
Protection of users out the service area
ESA
EC/Eurocontrol/FAA
EUROCONTROL
EC/ESA
12:45 – 14:00
Lunch
Objective 4
R&D cooperation on key SBAS technologies (continued)
14:00 – 17:00



17:00 – 17:10
ESA R&D program update
SQM User Error
L5 Signal Deformations (update)
ESA
ESA/DLR
Stanford
Coffee Break
17:10 – 18:00

SBAS & Ionosphere
o EGNOS 2012 observations
o Analysis results and planned activities
o IONO Working Group
ESSP
ESA
Stanford
Day 2- 24th of January
Objective 5
Support joint SBAS promotion
09:00 – 09:30



Objective 2
Global SBAS presentation / fact sheets
EGNOS Service Introduction status
EGNOS Coverage Extension Plan and new mission requirements
FAA
EC
EC
Forum for discussion on SBAS Standards
09:30 – 11:00


11:00 – 11:15
SBAS DFMC Definition and Framework
Group Discussion
FAA
All
Coffee Break
11:15 – 12:00


ICAO NSP status
Eurocae WG-62 Status and proposed Future efforts
12:00 – 13:30
Lunch
Objective 2
Forum for discussion on SBAS Standards
13:30 – 15:30
Update on SBAS/GNSS Standards



15:30 – 16:30




16:30
RTCA SC-159 Status and proposed Future efforts
SBAS L1/L5 SIS ICD (European activity results)
SBAS L1/L5 SIS ICD
EC
EC
MITRE/Stanford
ESA
Stanford
Other Business
SBAS IWG (SBAS for non-Aviation Users)
Review of Meeting Objectives and actual achievements
Summary and agreement on new Action Items
Future meeting schedule and location
End of Day 2 meeting
All
All
All
All
Day 3- 25th 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