Wide Area Augmentation SystemWide Area Augmentation System

Dan Hanlon

WAAS Program ManagerApril 2, 2003

What is WAAS?What is WAAS?

• WAAS Consists of:– 25 Reference Stations– 2 Master Stations– 2 Geosynchronous

Satellites– 3 Uplink Stations

• WAAS Augments The GPS Constellation To Meet The Necessary Integrity, Availability, Accuracy, And Continuity For Use In All Phases Of Flight.

How Does It Work?How Does It Work?

WAAS Components WAAS Components

WAAS BenefitsWAAS Benefits• Safety

– Vertical Guidance Available For All Runways Ends (CFIT)

– Situational Awareness (Air and Ground)– Low Altitude Routes

• Protection From Icing• Positive Guidance In Obstacle Rich Terrain

Benefits cont.Benefits cont.

• Cost Savings– Low Cost/High Capability Avionics Available to All

Users– Reduction of Redundant Ground Based Navigation

Aids

Benefits cont.Benefits cont.

• Efficiency– Precision Approach

• Back Up For All Current ILS Approaches (250/¾)

• Usable With Advanced Procedures

LNAV/VNAV350’

LPV 250’

ILS 200’

3o

Example Curved Approach withContinuous Descent

© 2002 The MITRE Corporation. All RightsReserved.

• WAAS RNP Can Provide Lower Minima At Airport

Benefits cont.Benefits cont.• Efficiency

– Provides High End Navigation Capability To All Users

– Advanced Arrival & Departure Procedures• Mitigate Impact on Noise & Environmentally Sensitive Areas

• Develop Non Interfering Arrival/Departure Routes in Class B and Other Airspace

WAAS AvailabilityWAAS Availability

ProceduresProcedures

• All GPS Stand-Alone Procedures are being Converted to Area Navigation (RNAV) Procedures

• Plan to have WAAS GPS Approaches to all Suitable IFR Runway Ends– Provide Vertical Guidance– Lower Minima?– Develop ~300/yr Until 2009

• Plan to use WAAS GPS Approaches for Future Copter Approaches to Heliports– Expect Considerable Improvement in Lower Minima

Procedures cont.Procedures cont.

• Approaches– 524 Published LNAV/VNAV Approaches

(3/6/03)– Expect to Have 700 LNAV/VNAV Procedures

Available at WAAS Commissioning

• Plan to Publish the First LPV Approaches by 9/03– Publish Approximately 300 LPV Approaches

per Year– Continue to Publish LNAV/VNAV Procedures

WAAS AvionicsWAAS Avionics

• Certified Receivers – UPS/AT– Chelton Systems– Others in Development

• Capstone (Alaska)– SFAR Approved (Mar

03)– Currently Equipping

Aircraft with WAAS AvionicsAble to Use WAAS Upon WAAS Commissioning

Capstone Installation

UPS/AT WAAS Sensor

Chelton Receiver

WAAS Receiver Functional ClassesWAAS Receiver Functional Classes

• Beta – Sensor Only. Does Not Have Navigation Function– Generates Position, Velocity, Time, With Integrity– Typically Provides PVT To An FMS Which Provides

Navigation Function• Gamma

– Typical Panel Mount Receiver– Beta Sensor Plus Navigation Function With Procedure

Database And User Controls• Delta

– Beta Sensor With Navigation Function That Provides Deviations To A Final Approach Segment Only

– Functions Like ILS (E.G., Does Not Support En Route Navigation)

Antenna Sensor(Beta)

NavigationComputer

Database

Controls

Position

Integrity

AlertsDeviations

DeviationsSteering

Displays

Autopilot

WAAS Class Beta ConfigurationWAAS Class Beta Configuration

Antenna Sensor(Beta)

NavigationComputer

Database

Controls

Position

Integrity

AlertsDeviations

DeviationsSteering

Displays

Autopilot

WAAS Class Gamma ConfigurationWAAS Class Gamma Configuration

Antenna Sensor(Beta)

Position

Integrity

AlertsDeviations

DeviationsSteering

Displays

Autopilot

ControlsDatabase

NavigationComputer

WAAS Class Delta ConfigurationWAAS Class Delta Configuration

WAAS Schedule GoalWAAS Schedule Goal

• WAAS Operational (LNAV/VNAV)– 95% of U.S.– Portions of Alaska– 350’ Minimum

• WAAS Operational (LPV)– 250’ Minimums

• WAAS Full Operating Capability– Full Continental U.S.– Most of Alaska– 250’ Minimum

• GPS L5– WAAS 200’ Minimums– Interference Mitigation

July 2003

September 2003

2006

~ 2013

SummarySummary

• WAAS Operating Continuously Since August 2000 And In Use By Over 1 Million Non-aviation Users

• Certified Avionics Are Available Now• WAAS Procedures Are In Place And Will

Continue To Be Developed• WAAS Will Be Commissioned For Use in the

National Airspace In July 2003

FAA GPS Product TeamWebsiteFAA GPS Product TeamWebsite

• For further information on the FAA’s Satellite Navigation Program, please visit our website at:

http://gps.faa.gov