GPS Augmentation Systems Status - gps.gov Aviation Administration GPS Augmentation Systems Status Leo Eldredge, GNSS Group Federal Aviation Administration (FAA) September 2009

Federal AviationAdministration

GPS Augmentation

Systems Status

Leo Eldredge, GNSS GroupFederal Aviation Administration (FAA)September 2009

Institute of Navigation (ION)1Federal Aviation

AdministrationSeptember 2009

FAA GPS Augmentation Programs



WAAS Architecture

38 Reference

Stations

3 Master

Stations

4 Ground

Earth Stations

2 Geostationary

Satellite Links

2 Operational

Control Centers



IntelsatGXV133W

TelesatF1R

107W

Inmarsat4F3 98W

GEO Satellite Coverage Plot

Localizer Performance Vertical (LPV)

Global SBAS Coverage



Airports with WAAS Supported Instrument Approaches with Vertical Guidance

As of Aug 27th, 2009

-1,822 LPVs serving 970 Airports

- 1049 LPVs to non ILS Runways - LPVs to 678 non-ILS Airports - 773 LPVs to ILS runways

WAAS Enterprise Schedule04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30FY

Development Operational

Technical Refresh Operational

JRC

Launch10/05

Operational

Operational

Launch9/05

Technical Refresh Operational

JRC

FOC

Launch09/08

Operational

Launch09/14

Operational

Launch09/16

Operational

Launch09/18

Operational

FLP Segment (Phase II)

LPV-200 Segment (Phase III)

Dual Frequency (Phase IV)

GEO #3 – Intelsat

GEO #4 – TeleSat Gap

Filler GEO

GEO #5 – TBD

GEO #6 – TBD

GEO #7 - TBD

Initial Test

Production

FOC

SLEP

Phase III Phase IV

Cutover

Operational SLEP

Standards Development User Transition Period

L5 Design L5 Implementation

GPS L5

WAAS

WAAS Avionics

Ph

ases

GE

OG

PS

M

od

ern

iza

tio

n

Ap

pro

ac

hD

eve

lop

me

nt

WAAS Procedure

Development

~5,218



Local Area Augmentation System (LAAS)

• Precision Approach For

CAT- I, II, III

• Multiple Runway Coverage At An

Airport

• 3D RNP Procedures

(RTA), CDAs

• Navigation for Closely Spaced

Parallels

• Super Density

Operations



GBAS Pathway Forward

• Cat-I System Design Approval at Memphis – Complete

• Cat-III Validation by - 2010

• Cat-III Final Investment Decision by - 2012



Agana, Guam

Frankfurt, Germany

Rio De Janeiro, Brazil

Malaga, Spain

LAAS/GBAS International Efforts

Sydney, Australia

Bremen, Germany



Future Considerations

GLONASS

GPS

Galileo (EU)

COMPASS



Two Civil Frequencies

• The ionosphere creates the largest source of uncertainty affecting today’s use of GPS for aviation

• When GPS L5 becomes widely available it will be possible for the user receivers to directly remove the ionosphere delay errors

• However, the two frequency combination amplifies the effects of other error sources

– More satellites tend to reduce the magnitude of the errors



WAAS Dual Frequency User Potential(No “RDM Constraint”)

38 US WRS

13 SA WRS

IFOR Threshold

38 US WRSIFOR Threshold

Current International Signal Plans

14

FutureCDMA signal

SBAS(US Europe

India Japan)

QZSS(Japan)

IRNSS(India)

COMPASS(China)

Galileo(Europe)

GLONASS(Russia)

GPS(US)

L1L5 L2

Compass & IRNSSIn S-band

1560 1570 1580 1590 1600 16101170 1180 1190 1200 1210 1220 1230 1240 1250 1260 1270 1280 1290 1300

Frequency (MHz)



Interoperability of Integrity

• Interoperability should be a goal not just for GNSS signals, but for integrity provision as well

– Augmentation systems already internationally coordinated

• Different service providers may select different design choices and offer different assurances

– However, it is important to establish a common understanding of GNSS performance characteristics and their relationship to provision of integrity

– Cooperation and transparency are essential

• Combining signals from multiple interoperable constellations can improve performance and availability

– Presents opportunity for a truly international solution

– Not necessarily dependent on any single service provider

– Seamless global coverage



GNSS Integrity Requirements

• Assure good nominal signal accuracy

– On order 1 m ranging accuracy

• Assure good availability of signals

– Assure most satellites working most of the time

• Assure good continuity of signals

– Less than 10-5/hour probability of unexpected outages

• Assure low integrity fault rates

– On order 10-5/SV/Hour

• Perform a fault modes and effects analysis

– Understand and make transparent potential faults and their effects

– Assure that multiple satellites do not have consistent errors at the same time

– Assure limited duration outages (e.g., an hour) of unexpected faults



ARAIM Results for 30 SVs & URA = .5 m

For VAL = 35m, NDP & Acc: 97.77% coverage at 99.5% availability< 50% > 50% > 75% > 85% > 90% > 95% > 99% >99.5% >99.9%

Longitude (deg)

La

titu

de

(d

eg

)

URA = 0.5m, Bias = 0.5m, URE = 0.25m, rBias = 0.1m

-150 -100 -50 0 50 100 150

-80

-60

-40

-20

0

20

40

60

80

99.5% VPL - 20.46 m avg., 35m avail = 99.99%< 15 < 20 < 25 < 30 < 35 < 40 < 45 < 50 > 50

Longitude (deg)

La

titu

de

(d

eg

)

URA = 0.5m, Bias = 0.5m

-150 -100 -50 0 50 100 150

-80

-60

-40

-20

0

20

40

60

80

ARAIM currently predicated upon a user update rate of ~ 1hour



Summary

• WAAS currently providing service to aviation in the U.S. National Airspace System

• LAAS system design approval for Category-I completing in September

• LAAS activity to continue to Category-II/III

• Dual Frequency GNSS Offers Significant Potential for Aviation

0.2 nm

(7)

0.2 nm(7)

0.2 nm

(7)

0.6 nm

(6)

1 nm

(5)

NIC

(10-7)

121 m

(8)

0.05 nm(8)

0.05 nm

(8)

0.05 nm

(8)

0.1 nm

(7)

NACp

(95%)

2.0 nm

IPA

2.5 nm

DPA

2.5 nm

DPA

3 nm

5 nm

Separation

Surveillance

(>99.9% Availability)

40m/10m16m/2mGLS Cat-IIIGBAS

40m/10m16m/4mGLS Cat-I

40m/35m16m/4mLPV-200

40m/50m16m/4mLPV

SBAS**0.1 nm*0.1 nmRNP (AR)

GPS

0.6 nm*0.3 nmLNAV

2 nm*1 nmTerminal

4 nm*2 nm

8 nm*4 nmEn Route

20 nm*10 nm

GNSS PNT

(99.0 – 99.999%)

Containment

(10-7)

Accuracy

(95%)

PositioningNavigation

(> 99.0% Availability)

RNP and ADS-B (RAD) Enabled with GNSS PNT

Dependent Parallel Approach (DPA)

Independent Parallel Approach (IPA)

Surveillance Integrity Level (SIL)

Navigation Integrity Category (NIC)

Navigation Accuracy Category

for Position (NACp)

*Operational requirements are defined for total system accuracy, which is dominated by fight technical error. Position accuracy for these operations is negligible.

** Containment for RNP AR is specified as a total system requirement; value representative of current approvals.

Documents

GPS Augmentation Systems Status - gps.gov Aviation Administration GPS Augmentation Systems Status Leo Eldredge, GNSS Group Federal Aviation Administration (FAA) September 2009