GNSS Integrity John Wilde CEO DW International

GNSS Integrity John Wilde CEO, DW International

Agenda • • • About DW International Basic GNSS Principles Navigation System Performance – RNP RAIM on the Ground - Performance Prediction GNSS RAIM/RNP Prediction Tool 2

DW International • Started in 2005 • Consultancy for: • Air Navigation • Civil Air Communications • Air Traffic Management In-house Expertise in Aviation • Array of External Consultants • International Presence • ISO 9001: 2008 Certified • 3

Expertise • • • Navigation (PBN) Airworthiness and Operational Approval Aviation Safety Communications Surveying / Geodesy Instrument Procedure Design Airspace Design GNSS Policy Making ATM Consultancy Spectrum 4

Consultancy • • RNAV 1 / RNAV 2 Navigation Specification PBN Criteria for PANS-OPS Editorial Reviews for ICAO PBN Manual + RNP AR Procedure Design Manual P-RNAV Safety Case RF Spectrum Expertise Technical Advisor to EUROCONTROL IFPP Member Chairmanship of CGSIC 5

Agenda • • • About DW International Basic GNSS Principles Navigation System Performance – RNP RAIM on the Ground - Performance Prediction GNSS RAIM/RNP Prediction Tool 6

The GPS Timeline L 5 L 2 C 2 nd Gulf War SA Switched Off GPS Fully Operational July 1995 1 st Gulf War KAL 007 Shot Down 1 st GPS Satellite Launched GPS Initial Approval December 1973 1978 1983 1991 1995 2000 2003 2005 2009 7

How does GPS work? 8

Multiple Satellites for Position 9

Error Sources Error Source GPS Error (m) Ephemeris 1 to 3 Ionosphere 1 to 7 Troposphere 0. 1 to 0. 5 Multi-path 0. 5 to 1. 5 Satellite Clock 1 to 2 Receiver Noise 0. 2 to 0. 3 10

Agenda • • • About DW International Basic GNSS Principles Navigation System Performance – RNP RAIM on the Ground - Performance Prediction GNSS RAIM/RNP Prediction Tool 11

Navigation System Performance - RNP Traditionally “box-based” • Mandatory equipment • Performance not specified explicitly • Move towards Required Navigation Performance or Performance-Based Navigation • Operator can meet requirements in ‘anyway he pleases’ • e. g. with GPS • Goal: Target Level of Safety • Risk of leaving containment area distributed amongst: • Accuracy • Integrity • Continuity • Availability • 12

Navigation System Performance - Accuracy 13

Accuracy: Lateral 14

Accuracy: Geometry 15

Accuracy: Geometry 16

Navigation System Performance - Integrity 17

Navigation System Performance - Continuity 18

Continuity risk is the probability of a detected but unscheduled navigation function interruption after an operation has been initiated • RAIM: detected failure causes loss of continuity but preserves integrity • 19

Navigation System Performance - Availability 20

Agenda • • • About DW International Basic GNSS Principles Navigation System Performance – RNP RAIM on the Ground - Performance Prediction GNSS RAIM/RNP Prediction Tool 21

RAIM on Ground - Performance Prediction • Average (expected) performance depends mainly on Geometry (time-varying) • Measurement quality (constant) • Satellite failure rate (constant) • • Geometry is predictable Expected performance is predictable • Prediction does not include effect of real-time events • • • Sudden satellite failures Can be performed on the ground as a pre-flight check 22

RAIM (integrity) Holes 23

Agenda • • • About DW International Basic GNSS Principles Navigation System Performance – RNP RAIM on the Ground - Performance Prediction GNSS RAIM/RNP Prediction Tool 24

GRPS : On-Demand Service GRPS = GNSS RAIM / RNP Prediction Service • Web interface and automated XML interface • • Current website implementation for GPS constellation only • • Future implementation for other GNSS to meet demand • e. g. GLONASS, Galileo, COMPASS Fully integrated XML solution for Airlines • Air Navigation Data Providers • Flight planning companies • • Both do RAIM predictions down to 0. 1 NM 25

RAIM in Aviation: ICAO RNP Requirements 26

GRPS • Dynamic and flexible • • High load capacity, high availability • • Tailorable to the requirements of the data provider and their client base Hosted in professional data centres, load-balanced Includes planned and short-notice outage information • Latest constellation almanacs and NANUs supplied by the US Coastguard All calculations are performed in real time and not on a pre-calculated grid • Routes and Airports capability • 27

GRPS: On-Demand Service • Both services support both RAIM prediction algorithms common in GPS devices: • Fault Detection (FD): Used by traditional RAIM to detect faults (differences between a satellite’s pseudo range measurement and its expected value) • Minimum 5 satellites in view • • Fault Detection and Exclusion (FDE): Used by newer GPS receivers to allow continued operation in the presence of a GPS failure • Minimum 6 satellites in view • Baro aided, SA on/off, mask angle, etc • Avionic specifics for RNP AR • 28

Architecture 29

GRPS: Comparison with AUGUR Coverage Area Constellation Status Check Constellation Visibility Check DWI GRPS ECAC Airspace Only Yes Global Yes RAIM Only Aerodrome Check Terminal: 1. 0 NM NPA: 0. 3 NM RAIM Only Route RAIM Check Max. Fidelity of RAIM/RNP Prediction Configurable Receiver Parameters RAIM/RNP Calculations Compliant with ICAO PBN Manual Aeronautical Data Provider En-route: 2. 0 NM Terminal: 1. 0 NM RAIM and RNP NPA: 0. 3 NM Terminal: 1. 0 NM En-route: 2. 0 NM MNPS RNAV 5 RNP 10: 10 NM RNP 4: 4 NM RNP(AR): 0. 3 - 0. 1 NM NPA 0. 3 NM RNP(AR) 0. 1 NM C 129 -FD C 145/146 -FDE Baro / Non-Baro Aided C 129 -FD/FDE, SA On/Off C 145/146 -FDE, SA Off Baro / Non-Baro Aided Partial Yes Jeppesen (Possible move to Jeppesen Eurocontrol’s EAD in 2012) GPS Constellation Data Provider USCG 30

GRPS Web Access https: //tools. dwint. com/grps/ Customisable – e. g. ICAO SAM Region 31

Eurocontrol • www. ecacnav. com 32

Web Tools • AUGUR • • SAFIRE • • Web-based RAIM Prediction Tool Web-based, secure communications Frequency Management Tool Final Approach Segment Database (FAS DB) • Final Approach Segment Data Block Tool – Webbased Tool to generate CRC values 33

RNAV Validation Tool • • • Desktop ground RNAV Procedure Validation application PANS-OPS criteria Flyability Noise contours Fuel Flow Emissions 34

GNSS Performance Monitoring System GPMS • Allows users to comply with ICAO Guidance – Annex 10 • • Requires Monitoring and Recording of GNSS Data as Navigation Aids and for incident investigation Localised GNSS Receivers • Wide Area RAIM Prediction • GNSS NOTAMS for State ANSP and Airspace users • Ionospheric data collection and alerting • 35

GNSS Performance Monitoring System • Incheon International Airport, Seoul, Korea Hong Kong International Aiport • 36

GNSS Performance Monitoring System 37

Obrigado - Any questions? john. wilde@dwint. com www. dwint. com 38