DFMC

1. DFMC Work Plan Update

2. Outline • Background / Purpose • Task Progress Review • Discussion areas

3. Background and Purpose • IWG has identified the need for a DFMC Definition Document outlining a requirements concept for Dual Frequency Multi-Constellation (DFMC) SBAS • A draft work plan to develop this document was presented at Ottawa 2012 (IWG-23) • Presented again at IWG-24 • This work plan status update • Identifies efforts in progress • Should assess progress based on presentations • Identifies areas with little to no effort

4. Tasks • Operational Concept • Operational Goals and Services • GEO Selection and Transition • Reversionary Modes • Identify Benefits • System Requirements • Interchangeable Satellites • Safety Strategy • Avionics Design Constraints • Interface Definition • Interface Requirements • Interface Control Document • Definition Document

5. Operational Goals and Services • Objectives • Identify minimum target operations and supporting services • Propose service classification schemes for coordination with standards bodies • Status • Initial proposed operational targets discussed at IWG 23. Documented in Work Plan Section 2 • Fairly well documented in Definition Document outline • Contains no new services or operations beyond current DO-229 • Need to update if there are specific changes for ADS-B or TBO

6. GEO Selection and Transition • Objectives • Enable SBAS interoperability when transition between different operations, GEO coverage volumes, SBAS service volumes, international airspace and state airspace. • Status • Briefing and white paper available on options provided at IWG-26 (Feb 2014) • Requires IWG discussion/guidance on narrowing options • Request comments by April 30, 2014 • Can develop specific recommended requirements based on SBAS selection method • White paper 2-4 months after decision on selection method

7. Reversionary Modes • Objectives • Identify minimum required avionics modes and supporting navigational services to support preferred fallback strategy and minimum operations. • Status • Briefing prepared by MITRE for IWG 24 • ESA brief (IWG 26) and white paper (April/May 2014) • Deliverables

8. Identify Benefits • Objectives • Identify benefits for ANSP and avionics manufacturers • Status • No definite plan to address • Any interest, commitment from new States • Support for SBAS reference stations • Approval of SBAS service based on dual-frequency

9. Interchangeable Requirements • Objectives • Identify technical issues necessary to support this capability • Derive requirements necessary to mitigate technical issues • Identify and quantify any resulting technical risks associated with this capability and the derived requirements. • Status • ESA Position Computation Equations • Definition of Inter System Issues (Geodetic References, Time References, Inter System Bias) • April/May input for DFMC Definition Document

10. Safety Strategy • Objectives • Explain high level safety strategy and clearly identify subsystem safety objectives (e.g. integrity and continuity performance targets) • Status • No drastic change from current SBAS standards on approach to safety (e.g. not reallocation of integrity between ground and airborne subsystems) • ESA Protection Level Calculations • Brief at IWG-26, April/May input for DFMC Definition Document • Threat list or modification of Safety Strategy effort not underway • Propose using threat listed in ARAIM paper (see additional briefing)

11. Avionics Design Constraints • Objectives • Identify key minimum design constraints which avionics must comply with to enable DFMC concept • Status • Briefed Signal Quality Monitoring and recommended correlation requirements (IWG-25, RTCA Oct 2013) • ESA working aviation error budgets

12. Interface Requirement • Objectives • Develop interface requirements • Status • Reached consensus on ICD changes • Need to document signal format changes and accompanying requirements • E.g. propose redlines to DO-229D, Appendix A which describes current signal specification

13. Interface Control Document • Objectives • Develop the message structure for DFMC GEO L1 and L5 SIS • Status • Reached consensus on ICD changes – Dec 2013 • Briefed at IWG 26 • Working on updated ICD • Recall previous SiS, transport layer effort

14. Definition Document • Objectives • Identify required Definition Document content and assign resources • Maintain Definition Document and populate with information when available • Status • Initial outline drafted. Briefing prepared by FAA for IWG 24. • Updated expected following white paper receipt April/May 2014 • Deliverables

15. Discussion Areas • Benefits for Dual-Frequency SBAS • Benefit of optional L5 ionosphere grid broadcast • Safety strategy • Threat list / threat identification • Effort required if desire to support operations more demanding than LPV-200 • Interface Requirements Document

16. Summary • Review progress of work plan • Provided updates based on presentation at IWG 26 • Identified work plan topics at risk • Discussed path forward • Please provide comments to • joseph.ctr.dennis@faa.gov • jason.burns@faa.gov

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