1. Welcome to Stanford! Civil Aviation Administration of China & Federal Aviation Administration

2. 2 Welcome to Stanford Ms. Lu Xiao Ping, Deputy Director General, ATMB Ms. Zhang Jing, Director, Inter. Cooperation Division, ATMB Mr. Li Xin, Director, R&D Division, ATMB Mr. Pan Yong Dong, Deputy Director, Planning Division, ATMB Mr. Cao Hui, Manager, Aeronautical Data Communication Company Mr. Cai KaiQuan, Engineer, ADCC Mr. Shi Le, Engineer, ADCC Mr. Chris Dufresne, Computer Engineer, FAA Mr. CJ Jones, FAA / ATO Mr. Dave Burkholder, FAA / ATO Mr. Sam El-Zoobi, FAA / ATO Mr. J.C. Johns, Navigation Director, FAA

3. 3 Agenda 7:30 Parking and Logistics 8:00Welcome from the FAA ATO International, Mr. David Burkholder 8:15Introductory Remarks and GPS/RAIM Objectives, Madame Lu 8:30Overview of FAA Satellite Navigation, Mr. J.C. Johns 8:45History of Stanford Involvement with FAA SatNav, Prof Per Enge 9:00Absolute RAIM, Dr. Todd Walter 9:30Break 9:45Civil Monitoring, Dr. Xingxin Gao 10:15GPS Modernization, Prof. Brad Parkinson 10:45Open discussion on potential for GPS RAIM cooperation between FAA, Stanford and CAAC ATMB 11:30Lunch at the Faculty Club 1:00Closing Remarks and document agreed to Next Steps for presentation at JATSG/6 on 4/21 (FAA, ATMB and Stanford)

4. History of Stanford Involvement with FAA Satellite Navigation: From 1990 to the GEAS for the Civil Aviation Administration of China by Per Enge (with the help of many) April 20, 2009

5. 5 User Segment Control Segment The Global Positioning System

6. 6 Stanford Scope: Maximize Aviation Benefits from GNSS Worldwide approach capability with vertical guidance, but no airport equipment. Worldwide landing capability (Cat. I/II/III) with high availability. Robust against –Faults –Rare normal –Ionosphere –Scheduled RFI –Unscheduled RFI Safety Analyses

7. 7 Very Brief History of Stanford Work for the FAA 200020101990 Brad Parkinson gathers a GPS team at Stanford Early work on LADGPS, WADGPS & RAIM LADGPS flight trials based on in-track pseudolites WADGPS flight trials based on vector corrections Co-chair RTCA WG-4 LADGPS flight trials based on airport pseudolites Work on operational benefits Tunnel in the sky displays, wake vortex, CSPA, etc. Design for safety: faults & rare normal events Interaction with prime contractors WAAS integrity performance panel (WIPP co-chairs) LAAS integrity performance panel (LIPP) All of the above was funded by the FAA through Cooperative Agreements 93-G-004, 95-G-005, 97-G-012, 00-G-012 & 08-G-007. WAAS Operational LAAS Operational

8. 8 First 10 Years Focused on Flight Trials

9. 9 Second 10 Years: Faults & “Rare Normal” Events October 1993 modulation fault 40 notable iono events during the last solar peak RFI events: San Diego St Louis Santa Cruz Clock “runoffs” 7/28/01, 5/26/03 6/11/03 & more April 10, 2007 ephemeris fault & 24 smaller faults over the last 5 years

10. 10 Truncation of the Error Tail 051015202530354045 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 User Vertical Position Error (meters) PDF ground screening (Cat I) air & ground screening (Cat I/II/III) dual freq. GBAS (Cat I/II/III)

11. 11 Evolution of GNSS-Based Safety L1 Only RAIM SBAS GBAS Dual freq. SBAS & GBAS 24 SVs Minimum 10 -4 from GNSS Dual freq. ARAIM Open service GPS: 30+ Slots Multi-constellation 10 -4 from GNSS 202020302010 GNSS Integrity Within GPS IIIC (1 st 16) ++, or GNSS Safety of Life 24 SVs (GPS alone) 10 -7 from GNSS

12. 12 Our Current Emphasis: L5 & New Constellations Dual freq. SBAS & GBAS 24 SVs Minimum 10 -4 from GNSS Dual freq. ARAIM Open service GPS: 30+ Slots Multi-constellation 10 -4 from GNSS 202020302010

13. 13 Absolute Receiver Autonomous Integrity Monitoring (ARAIM) for 2020 VPL GPS Compass Galileo GLONASS VPL

14. 14 FAA Supported Graduates of the GPS Lab (1/2) University Professors Penny Axelrad, UColorado Changdon Kee, SNU Boris Pervan, IIT Glenn Lightsey, UT Austin Demoz Gebre-Egziabher, UMinn. Gabe Elkaim,f UCSC Shau-Shiun Jan, Taiwan David Bevly, Auburn U. Novariant* Clark Cohen Stewart Cobb Dave Lawrence Paul Montgomery Mike O'Connor Tom Bell Frank Bauregger Televigation*, Y.C. Chao Traxis* Roger Hayward Jock Christie Rich Fuller Nav3D* Andy Barrows Keith Alter Chad Jennings Rossum* Matt Rabinowitz Guttorm Opshaug Ju-yong Do M Shift*, Awele Ndili Mapbar.com*, Donghai Dai Meta-VR*, Andrew Hansen NordNav* Per-Ludwig Normark Sasha Mitelman OlinkStar*, Junlin Zhang

15. 15 FAA Supported Graduates of the GPS Lab (2/2) Medium Size Companies Jiyun Lee Ping-Ya Ko Yeou-Jyh Tsai Jaewoo Jung Gang Xie, SiRF Alexander Mitelman, NordNav Ung-Suok Kim Michael Koenig, SiRF Lee Boyce: Consultant Seebany Datta-Barua, ASTRA Euiho Kim, Wilcox Hiroyuki Konno, TopCon Harris Teague, Seagull Sharon Houck, Seagull University or Govt. Researchers Sam Pullen Eric Phelts Sherman Lo Juan Blanch Konstantin Gromov, JPL Eric Olsen, Johns Hopkins APL Jenny Gautier, UC Ran Gazit, Rafael Hiro Uematsu, NASDA Andrew Hansen, FAA Volpe Large Companies Andy Rekow, John Deere Eric Abbott: L3

16. Updated Stanford Work Plan for FY09 for JC Johns by Per Enge (with the help of many) April 20, 2009

17. 17 Evolution of GNSS-Based Safety from the GEAS L1 Only RAIM SBAS GBAS 202020302010 Task 1: Optimize Single Frequency WAAS Task 2: SDM from WAAS to LAAS Task 3: GAST-D Task 4: DCPS

18. 18 Task 1: Optimize Single Frequency WAAS Provide added robustness for upcoming solar maximum –Work with Raytheon to implement kriging –Retune algorithms and storm detectors to ensure maximum CONUS availability Work with Raytheon to implement improved SQM for better continuity Provide training to Oklahoma City to ensure they understand intent and design of WAAS algorithms

19. 19 PRN Number Task 2: Use WAAS SDM to Validate Nominal Model for New LAAS SVs WAAS SDM Trip Threshold SV11 & 23 cause LAAS SDM to trip during SLS4000 development

20. 20 Task 2: Use WAAS SDM to Validate Nominal Model for New LAAS SVs [From WAAS PAN report]: Increasing trend used to confirm SLS-4000 SDM was operating correctly by flagging and excluding PRN 11.

21. 21 Task 3: GAST-D is Seeking Iono Freedom Ionosphere Anomaly Threat Model 51530456590 SV elevation angle (deg) Slant iono. gradient bound (mm/km) 100 200 300 375 425 Flat 375 mm/km Flat 425 mm/km

22. 22 Task 3: GAST-D Truncates the Error Tail

23. 23 Task 3: GAST-D Truncates the Error Tail 051015202530354045 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 User Vertical Position Error (meters) PDF ground screening (Cat I) air & ground screening (Cat I/II/III) dual freq. GBAS (Cat I/II/III)

24. 24 Task 3: GAST-D Availability Tool GPS SV almanac LAAS ground and user PR error models Compute User Protection Levels for current SV geometry Increment availability counters & terminate outage counters Are GAST-D req’ts. met? Yes No Loop through all outage cases (0, 1, 2, 3 SV out) Loop through all time epochs over 1 day Loop through 12 U.S. airport locations Increment outage counters Availability requires: VPL ≤ 10-meter VAL max. S vert constraints met max |S vert |  3.0 max |S vert | + 2 nd max |S vert |  5.0

25. 25 Task 3: GAST-D Availability vs Constellation

26. 26 Task 3: GAST-D (L1-only CAT II/III) Fall 2008 review led by Jason Burns & John Warburton –SU, IIT, & other KTAs reviewed GAST-D technical status –Identified issues that need further study (e.g., multiple faults, time-to-alert) SU supporting FAA review of ionosphere anomaly mitigation alternatives ICAO/RTCA technical concept validation desired by end of 2009

27. 27 Task 4: DCPS Latest LAAS MOPS (DO-253C) limits DCPS to horizontal navigation (i.e., no VPL for DCPS) Further changes needed - seek best combination of several options: –Implement a “screening HAL” of 50 – 200 meters  below this value, HPL is not guaranteed to bound worst-case HPE –Add airborne geometry screening via max. S horiz (similar to GAST-D), min. N sat, or max. (N LGF_corr – N sat ) –Add airborne RAIM integrity monitoring (for DCPS only) These include changes to MOPS and to iono. threat model (relative to PA  1 SV impact only)

28. 28 Evolution of GNSS-Based Safety Dual freq. SBAS & GBAS 24 SVs Minimum 10 -4 from GNSS 202020302010 Task 5: Dual freq WAAS (L5 Roadmap) Task 6: Dual freq GBAS & JPALS

29. 29 Aviation Benefits from New Constellations & Signals Worldwide approach capability with vertical guidance, but no airport equipment. Worldwide landing capability (Cat. II/III) with high availability. Robust against –Ionosphere –Scheduled RFI –Unscheduled RFI –Malevolent RFI

30. 30 Task 5: Dual Frequency WAAS Convert Orange to Green

31. 31 Task 5: Dual Frequency WAAS Finalize & support the L5 transition plan based on –L5 roadmap meetings –L2 semi-codeless sunset –Support L1/L5 avionics –Meetings with service providers, RTCA & Eurocae Publish scintillation white paper based on: –International working group –Jiwon Seo: outage statistics & correlation –Tsung-Yu Chiou: receiver design L5 SBAS MOPS development at RTCA & EUROCAE –Determination of message contents and formats –Determination of user algorithms –Coordination with receiver manufacturers

32. 32 Task 6: Dual-Freq. LAAS Combines Divergence- Free & Ionosphere-Free Smoothing

33. 33 GPS SIS Correction MRCC  -Monitor Database VDB Message Formatter & Scheduler VDB RX VDB Monitor VDB TX LAAS SIS DQM Average MQMSmooth Executive Monitor (EXM) LAAS Ground System Maintenance A B LAAS SIS SISRAD SQR SQM Removed in JPALS– air and ground receivers have similar designs Changed to divergence-free (DF) smoothing in LDGPS –iono-free (IF) smoothing and LAAS-like SF smoothing are backups JPALS includes multiple corrections for L1 vs. L2 and different smoothing types Multiple sets of B-values are computed and monitored In JPALS, adjust thresholds based on observed local RF interference Task 6: Land-Based JPALS Ground Facility

34. 34 Evolution of GNSS-Based Safety Dual freq. ARAIM Open service GPS: 30+ Slots Multi-constellation 10 -4 from GNSS 202020302010 GNSS Integrity Within GPS IIIC (1 st 16) ++, or GNSS Safety of Life 24 SVs (GPS alone) 10 -7 from GNSS Task 7: System Def., Requirements & PL equations Task 8: Experimental Validation Task 9: International outreach Task 10: F/A-18 Hornet

35. 35 Task 7: System Definition ARAIM for 2020 VPL GPS Compass Galileo GLONASS VPL

36. 36 Task 7: System Definition ARAIM for 2020 GPS GLONASS Compass Galileo Ground Monitors dual frequency open service Air Traffic Status Ground Control 1.How do we close the loop? through Air Traffic 2.What do we ground monitor? URA & biases 3.How often do we close the loop? once per hour 4.What monitor network do we use? civil monitoring net 5.What do we ask of other service providers? same as us

37. 37 Task 7: System Definition 2030: GPSIII C GPS GLONASS Compass Galileo Ground Monitors dual frequency PPS Ground Control 1.How do we close the loop? through the GPS SVs 2.What do we ground monitor? ephemeris + URA to 10 -7 3.How often do we close the loop? once per minute (RRAIM) 4.What monitor network do we use? GPS 5.What do we ask of other GNSS service providers? Not so much (ARAIM?)

38. 38 Task 7: Proposed VPL Equations GPS IIIC ARAIM

39. 39 Task 7: Proposed Translation from Probabilities to Ground Monitoring

40. 40 Task 7: Assertions Under Consideration 1. Ergodicity 2. Smoothness 3. Short Temporal Correlations 4. Symmetry 5. Independence of Errors 6. Full Threat Analysis 7. Corrective Action

41. 41 Task 7: System Definition, Requirements & Protection Level Equations Continue work briefed by Todd Walter at February 2009 GEAS –Finalize URE definition –Finalize URA monitoring –PL equations for multi-constellation ARAIM –PL equations for GPS IIIC Seek wider review Coordinate with PSICA group to ensure FAA assurance requirements are being monitored and met.

42. 42 Task 8: Validate Civil Monitoring (Collaboration with FAATC & AMTI) ARAIM 99.5% coverage 24-12427-12730-130 No Real Time Monitoring 3.7%27.5%9.56%87.9%79.8%99.6% 8 stations50.8%88.3%71.5%96.7%98.7%100% 38 stations71.2%98.9%90.0%100%99.9%100% Civil monitoring is a trade between: Constellation size Robustness to SV failures Network size (URA bounding)

43. 43 Azimuth/Elevation Control Task 8: Validate Civil Monitoring of Signals (Collaboration with FAATC & AMTI) L-band Feed Cavity Filter Nova for Windows Satellite Tracking Software Agilent Vector Signal Analyzer (VSA) Low Noise Amplifier 45dB 15 m cable Digital filter bank with control circuits Automatic data recording based on triggers

44. 44 Task 8: Validate Civil Monitoring of Measurements (Collaboration with FAATC & AMTI) Objectives –Nominal range errors & URE –Detect & characterize range error & URE blunders Challenges –Compute range error without post-processed truth –Volume of data and computational load Milestones –MATLAB Interface is ready –Integrate the algorithm within the current monitoring –Migration from nationwide network to worldwide network –Migration from L1/L2 to L1/L5

45. 45 Undetected Fault Detection Process Task 8: Validate Flight Performance

46. 46 Task 9: International Outreach to Enable Multi-Constellation ARAIM Key: common understanding of providers responsibility All parties need to participate in requirement development Each constellation can choose level of performance Performance must be monitored to enable ARAIM New document for constellation requirements New document for avionics requirements –MOPS & SARPS –PL equations –Message contents

47. 47 Task 9: International Outreach (Schedule for next 4 months) March 2-3 ICG Workshop on GNSS Interoperability: Benefits of multi- constellation ARAIM and requirements from GNSS service providers March 3-5 Munich Satellite Summit: GEAS vision and benefits of multi-constellation ARAIM March 25-26: First meeting of Working Group C on interoperability of integrity service provision. April 2-4: Outreach to African nations on GNSS - aviation applications and the importance of understanding ionospheric behavior. Emphasis on getting measurements during the upcoming solar maximum. April 2-4: SBAS iono working group meeting. April 20: Civil Aviation Administration of China ATMB will visit Stanford (HoD: Deputy Director Madam Liu) April 21-23: Eurocae WG-62 is having substantial discussion on the use of multi-constellation ARAIM for vertical guidance. May or June: IWG to be hosted at Stanford. Will discuss L5 plans June 23: RTCA WG-2 need to start serious work on L5 MOPS

48. 48 Task 10: Naval Aviation Enterprise has use for LPV worldwide. What research or study is required to certify the system? Joint testing? ARAIM with one constellation SBAS in coverage SBAS/ARAIM in mixed WAGE based URE Availability/integrity requirements in theatre TIM at Stanford in early April F/A-18 Hornet

49. 49 Optional Task 11: Security Against DoS & Spoofing Attacks: Tri-lateration Based on Mode-S Bring the safety perspective early on. What VALs & HALs can be supported? Preliminary FMEA