Overview of FAASatellite Navigation Transition

and Backup Strategies

Int’l Loran Association

October 28, 2002

Navigation

Communications Surveillance

TheSeparation

SafetyTriad

Three Legs of the Safety Stool

Safety First and Foremost

Drivers for Transition and Backup Strategy

• Workload within interference area• Sustaining separation

• Radar• Non-radar

• Assuring safe recovery and landing of aircraft in weather• Minimizing disruption of air transportation to reduce threat• Minimum investment for users in backup capability

Issues During an Interference Event

• Response time in detecting size of disruption• Will controllers know size of interference area quickly to

tactically make adjustments?• How do pilots get the information to make route change

decisions?• Controller workload• Pilot workload• Response time to find and shut down interference• Terrain avoidance in interference area in weather

• En route low altitude RNAV routes• Terminal maneuvering

• Procedural separation in absence of navigation

General Assumptions

• DoD needs continued TACAN/DME/ILS• Precision landing capability (ILS) at least on one runway

at those airports necessary for recovery of aircraft during an interference event

• All Category II/III ILS systems retained• New runway landing capabilities can be served by ILS,

GPS(WAAS) or GPS(LAAS)• Approach lights retained where Category I ILS’s shut off• Sufficient VOR’s retained for VOR-VOR direct navigation

and landing with VOR non-precision approach at selectedairports (minimum operating network)

• DME’s retained to support INS/FMS redundancy• Nav coverage richer where surveillance is limited

© Mitre CAASD

Lack of SurveillanceCoverage

Greater navigation infrastructure retained where surveillance coverage is lacking for low altitude operations

Secondary SurveillanceCoverage at 6,000 ft AGL

Instrument Ops Percentages

• Top 200 Airports: 92% of Instrument Ops• Top 250 Airports: 95% of Instrument Ops• Top 300 Airports: 97% of Instrument Ops• Top 350 Airports: 99% of Instrument Ops

System Disruption

Like

lihoo

d of

Occ

urre

nce

Threat

Where is aviation on the curve?

TechnologyExists

Scenarios publicly known• Ground emitter• Intermittent emitter• Airborne emitter

??

?

?

How much “insurance”is needed to providecritical Infrastructureprotection?

OperationalContingency

BackupCapability

RedundantCapability

Operations Disruption

Threat Mitigation

Intentional Interference Event

Scaled Response

ProceduresOnly

VORMinimum Operating Network

Long-Range NDB’sILS

DME-DMEIRS/FMS

FMSILS

LORAN as a backup

Best theoretical Part 91 backup• RNAV backup for RNAV • Integrated antenna with GPS• One sensor in an integrated avionics package• Capable of providing alternative independent path for

differential corrections for GPS• Coverage in mountainous terrain for navigation and

differential correction for GPS• Reduced number of VOR’s below minimum operating

network

But….

LORAN X

• Updated ground infrastructure must continue• Not the LORAN C avionics as flown today• Loran C only useful for en route nav• Existing avionics declining as GPS overtakes panel space

in aircraft • Must be able to support non-precision approach• Meets availability though all-in-view receiver

• Each transmitter stick used instead of chains• H-field antenna for improved signal-to-noise (p-static)• Affordable as card in GPS box, not stand alone receiver• Avionics in 5 – 7 years (no MASPS/MOPS or TSO)• High market risk even with a DOT decision to continue

LORAN C

18,200 remaining LORAN-C VFR receivers 8,735 remaining IFR receivers remaining

VOR Proposal for Minimum Operating Network

• Victor Airways and Jet Routes begin reduction in 2010leading to no airways by 2014

• Replaced with VOR-VOR direct aids and Airport VOR aids• Airport VOR supports either VOR NPA, or VOR radial to ILS• Minimum Operational Network of VOR’s attained by 2014

No location in the CONUS further than 75 miles from VORat 5,000 feet AGL line-of-sight

• Mountainous locations treated differently due to altitude andicing concerns

• Replace/relocate MON VOR’s and reduce impact of maskingradials from 2007 through 2012

Current VOR Coverage 1008 VOR/VORTAC/VOR-DME

5000 ft AGL 0

1

2

> 3 © 2002 The MITRE Corporation. All Rights Reserved.

NumberVisible

VOR Backup Coverage - 429 VOR/ VORTAC/VOR-DME (177 + 252 Fillers)

5000 ft AGL 0

1

2

> 3 © 2002 The MITRE Corporation. All Rights Reserved.

NumberVisible

Existing DME Coverage 930 FAA DMEs (VORTAC/VOR-DME)

18,000 ft MSL 0

1

2

> 3 © 2002 The MITRE Corporation. All Rights Reserved.

NumberVisible

671 Airports with at Least One ILS

© 2002 The MITRE Corporation. All Rights Reserved.

1000’ MSL Ground LevelVOR 1VOR 3

5000 AGL

InterferenceArea

4000’ MSL4000’ MSL

1

23

Airport VOREn Route VOR

4

1. Request Climb orRadar Vector

2. Climb up to 5000’ AGL3. Proceed Direct to VOR4. Continue to next VOR5. Continue to next VOR6. Free of Interference7. Request RNAV and

Altitude Change

Backup RedundancyContinue Through AreaAs Planned Using RNAV

6000’ MSL

Likely Civil User Equipage(En Route Through Non-precision Approach)

Satnav

GPS/inertial(or GPS/WAAS)

GPS(or GPS/WAAS)

GPS/WAAS

Ground-basedNavigation Backup

FMS (DME/DME orinertial)RNP/RNAV

FMS (DME/DME)RNP/RNAV

(1) VOR or(2) Loran RNAV or

FMSNo inertial

No FMSor inertial

FMS withinertial

CurrentAvionics

Add Retain

(3) Ops Contingency

Satnav

GPS/LAAS

GPS/WAAS

GPS/WAAS

Ground-basedNavigation Backup

Scheduled OperationsLarge Airports

CurrentOperations

Add Retain

ILSCat I/II/III200 feet and ½ mile

Scheduled OperationsMany Airports

250 feet and ½ milewith approach lights

250 feet and ¾ milewithout approach lights

Unscheduled OperationsMany Airports

ILS/Cat I

200 feet and ½ mile

Likely User Equipage(Precision Approach)

(1) ILS/Cat I or(2) Ops Contingency

Retain on at least one runwayILS – CAT I and Localizer Only

02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20

TACAN (includes DME)

DME (VOR/DME and Stand Alone)

Minimum Operating NetworkVOR

ILS – CAT II/III Current runways retained for capacity

Long Range NDB – Alaska and Coastal

GPS IIIGPS

WAAS - 250 ft & ¾ mile vis (LPV)3rd GEO

>

LAAS CAT I

LAAS CAT II/III R&D Required

6 airports + options for 0 to 40 per year

LORAN ??? Decision on Continued Use In Late 2002

117 > 125

1,168 > 546

1,033> 500

878596

> 930596

WAAS - GLS

L5 Usable

>

Instrument Approaches and WAAS• The intent of WAAS was to provide three levels of service for instrument approaches:

– GLS (GPS Landing System)• Equivalent of ILS• Requires 40 m HAL and 12 m VAL• Requires LAAS

– LNAV/VNAV(Lateral/Vertical Navigation)• Requires 556 m HAL and 50 m VAL• Requires WAAS or Baro/VNAV (GPS or DME/DME and Baro)

– LNAV (Lateral Navigation)• Requires 556 m HAL

– No vertical guidance (non-precision approach)• Requires GPS, WAAS, or DME/DME LNAV

• New capability from GPS/WAAS– LPV (Lateral Precision with Vertical Guidance)

• Realizes a 40 m HAL and 50 m VAL• Provides lower minimums at more runway ends• Requires WAAS

Horizontal and Vertical Protection Required

LNAV/VNAV - RNP .3 (556 m horizontal by 50 m vertical)

LPV (40 m horizontal by 50 m vertical)

GLS (40 m horizontal by 12 m vertical)

Full GPS Landing Systems (GLS) will be available from LAAS and when the new L5 radio frequency is operationalfrom the GPS satellite constellation

V

H

5073 runway ends at 1534 airports

LPV and LNAV/VNAV Height above Touchdown (HAT)

0

500

1000

1500

2000

2500

3000

3500

250-

258

259-

327

328-

395

396-

465

466-

534

535-

603

604-

740

More

Obstac

les

Preve

nt

Approac

h

HAT (ft)

Nu

mb

er o

f R

un

wa

ys

LNAV/VNAVLPV

© 2002 The MITRE Corporation. All Rights Reserved.