Presentation is loading. Please wait.

Presentation is loading. Please wait.

GNSS Development Status and Future Work Eric Chatre, EC/ESA Rapporteur Technical WG, GNSS Panel Agenda Item 6.

Similar presentations


Presentation on theme: "GNSS Development Status and Future Work Eric Chatre, EC/ESA Rapporteur Technical WG, GNSS Panel Agenda Item 6."— Presentation transcript:

1 GNSS Development Status and Future Work Eric Chatre, EC/ESA Rapporteur Technical WG, GNSS Panel Agenda Item 6

2 Outline GNSS Elements GNSS Performance Requirements –Definition of parameters –Relationship betweens parameters Integrity Principles GNSS Standards Future Work

3 GNSS Elements GPS GLONASS Core Constellations Augmentations ABAS SBAS GBAS IOR

4 Aircraft-Based Augmentation System (ABAS) Stand-alone technique implemented in user equipment/software No accuracy improvement, lateral guidance only Provides integrity based on consistency check Needs redundant satellite measurements (5 or more satellites in view with good geometry) Integrity only Performance and availability limited to some phases of flight

5 Satellite-Based Augmentation System (SBAS) Objectives –Improve accuracy of GPS or GLONASS by providing corrections for Satellite errors : clock and ephemeris Ionospheric errors : model over a geographic area –Provide integrity information –Lateral and vertical guidance –Improved availability,

6 Satellite-Based Augmentation System (SBAS) (cont.) Architecture –Network of stations covering a wide area (e.g. continent) –Transmission of information to users through geostationary satellites Coverage and Service areas –Coverage : Wherever the geostationary signals are received –Service : Wherever operations have been approved by States

7 SBAS Architecture ReferenceStations Master Station UplinkStation GEO GPS SBASMessage

8 Ground-Based Augmentation System (GBAS) Objectives –Improve accuracy of GPS or GLONASS by providing for each satellite a composite correction Satellite errors : clock, ephemeris correction valid locally Ionospheric errors : local correction Tropospheric errors : local correction –Provide integrity information

9 Ground-Based Augmentation System (GBAS)(cont.) Architecture –Ground Reference Station (typically 1 per airport) –Transmission of information to users through a VHF data link (108 to 118 MHz) Coverage –Approach area (ILS like coverage) –Terminal area (positioning service)

10 GBAS Architecture GPS and/or GLONASS, GEOs User Reference station and VDB VHF DATA LINK

11 Aviation Performance Requirements for GNSS (signal-in-space) Phase of Flight Accuracy (95%) Integrity RiskContinuity Risk Availability En RouteH: 3.7 Km 1x10 -7 /h1x10 -4 /h to 1x10 -8 /h 0.99 to TerminalH: 0.74 Km NPAH: 220 m APV IH: 16 m V: 20 m 2x10 -7 /App8x10 -6 / 15s APV IIH: 16 m V: 8m Cat IH: 16 m V: 6 to 4 m Cat II/III Surface Ops Under Development

12 Interpretation of parameters Accuracy : Characterize typical behavior of the system in presence of nominal error components Integrity : Limit risk of abnormal behaviour of the system due to errors resulting from system failures -Integrity Risk -Alert Limit -Time to Alert Continuity : Limit risk of losing the service unexpectedly Availability : Accuracy + Integrity [+ Continuity]

13 Relationship between parameters Integrity Accuracy Continuity Availability Availabilty -Vertical accuracy/integrity is usually the main driver -Decreases as accuracy increases -Decreases as alert limit gets smaller GNSS performance is variable : -in time -in space -New approach to ensure integrity for all users -Protection Level concept

14 Integrity principles Alert Limit Computed Position User Computed Protection Level Protection Level > Alert Limit Alert Protection Level < Alert Limit No Alert Probability

15 GNSS Standards, Procedures, Guidance Material Standards and Recommended Practices (ICAO Annex 10, Vol I) GNSS NOTAMS and Phraseology (ICAO Annex 15, PANS-ABC Doc 8400, PANS- ATM Doc 4444) Procedure Design Criteria (PANS-OPS, Doc 8168) Geodetic Reference Datum and Data Base Requirements (ICAO Annexes 4,11,14 &15, WGS-84 Manual Doc 9674) Information and guidance on implementation (GNSS Manual) Industry Standards (RTCA and EUROCAE MOPS/MASPS)

16 Industry Standards The main actors are : –RTCA in the US, Special Committee 159 –EUROCAE in Europe, Working Group 28 The Documents –Minimum Operational Performance Specifications (MOPS) –Minimum Aviation System Performance Standards (MASPS) Existing Standards –ABAS/Basic GNSS receiver : DO-208 / ED-72 / (J)TSO- C129A –SBAS receiver : DO-229 C / TSO-145A/146A –GBAS Cat I receiver : DO-253A –Multi-Mode Receiver including GBAS : ED-88A

17 Future Work Evolution of currently standardized GNSS elements GPS modernization with additional civil signal on L5 frequency ( MHz) GLONASS modernization (GLONASS K) with additional civil signal in the MHz band Extention of SBAS standards to accomodate new signals Extention of GBAS standards to accomodate new signals and cover Category II/III and surface operations

18 Future Work (cont.) New GNSS elements GALILEO system with 3 civil signals and a dedicated integrity service Ground-Based Regional Augmentation System (GRAS)


Download ppt "GNSS Development Status and Future Work Eric Chatre, EC/ESA Rapporteur Technical WG, GNSS Panel Agenda Item 6."

Similar presentations


Ads by Google