gps augmentations and enhanced loran: infrastructure precision and reliability

GPS Augmentations and Enhanced Loran: GPS Augmentations and Enhanced Loran: Infrastructure Precision and ReliabilityInfrastructure Precision and Reliability

Asia GNSS Workshop

Seoul, Korea - November 4, 2004

James J. Miller

DOT Office of the Secretary

Asia GNSS Work Shop – Seoul Nov. 4, 20042

OverviewOverview

GPS Augmentations & ApplicationsGPS Augmentations & Applications Wide Area Augmentation System (WAAS)Wide Area Augmentation System (WAAS) Local Area Augmentation System (LAAS)Local Area Augmentation System (LAAS) Nationwide Differential GPS (NDGPS)Nationwide Differential GPS (NDGPS)

Loran developments in the U.S.Loran developments in the U.S. Loran Today Modernizing Loran Achieving “eLoran”


GPS Augmentations & ApplicationsGPS Augmentations & Applications

Power Grid

Interfaces

Personal Navigation

Trucking &

Shipping

Surveying &

Mapping

Communications --Network

Synchronization

and Timing

Fishing &

Boating

Railroads

Off shore

Drilling

Aviation

Recreation

Satellite Ops --Ephemeris, Timing


New Civil Applications New Civil Applications Continue To EmergeContinue To Emerge

• Child safety

• Wireless E-911

• Open pit mining

• Power grid management

• Spacecraft control

• Intelligent Transportation Systems


Current GPS Civil CapabilitiesCurrent GPS Civil CapabilitiesApplications Integrity Availability Accuracy

Ocean transitCoastal navigationInland waterwayHarbor entrance & approachHighway navigationEmergency ResponseTransit vehicle managementRailroad train controlOceanic en routeDomestic en routeNon-precision approachesPrecision approaches

Mar

itim

eL

and

Avi

atio

n

Requirements can be Requirements are not met

met by GPS alone by GPS alone


GPS Civil Capabilities GPS Civil Capabilities with Augmentationswith Augmentations

Application Integrity Availability AccuracyOcean transit GPS GPS GPSCoastal navigation GPS GPS GPSInland waterway NDGPS NDGPS NDGPSHarbor entrance & approach NDGPS NDGPS NDGPSHighway navigation GPS GPS GPSEmergency Response GPS GPS GPSTransit vehicle management NDGPS NDGPS NDGPSRailroad train control NDGPS NDGPS NDGPSOceanic en route GPS GPS GPSDomestic en route GPS WAAS GPSNon-precision approaches GPS WAAS GPSPrecision approaches WAAS/LAAS WAAS/LAAS WAAS/LAAS

Mar

itim

eL

and

Avi

atio

n

Requirements can be Requirements are met by

met by GPS alone GPS plus augmentations


Differential GPS (DGPS)Differential GPS (DGPS) ConceptConcept

ReferenceReferenceStationStation

.


Wide Area Augmentation System (WAAS)Wide Area Augmentation System (WAAS)

• Improves efficiency/capacity of airspace system– Advanced arrival and departure procedures

– Promotes airspace redesign

• Safety is most significant benefit– Vertical guidance at all runway ends

– Improves 3D situational awareness

• GPS/WAAS procedures in place

• Certified avionics are available now

• Improved access to airports for general, commuter, and business aviation

• Allows reduction of ground- based navigation aids

LNAV/VNAV 350’

LPV 250’

ILS 200’

3o


WAAS StatusWAAS Status

Commissioned for IFR En Route Operations - July 10, 2003 Lateral Guidance

– 100% of CONUS, Alaska, Hawaii, Puerto Rico Vertical Guidance

– 95% availability in CONUS & portions of Alaska

– LNAV/VNAV approaches (350’ minimums)

– LPV approaches (250’ minimums) first published - Sep 2003 WAAS Expanded LPV Coverage 2008

– Full continental U.S.

– Most of Alaska GPS Modernization ~ 2015

– L5 frequency

– WAAS 200’ minimums

– Interference mitigation


Local Area Augmentation System Local Area Augmentation System (LAAS)(LAAS)

• Precision approach for Category I, II & III• Multiple runway coverage• Complex procedures• Guided missed approaches• Guided departure procedures• Aircraft surface navigation


LAAS directed to be R&D program– CAT I contract becomes focused on integrity and

safety• Complete integrity design report and FHA

– CAT II/III Research and Development• GNSS/Inertial, EVS, RADALT integration study • Dual frequency LGF design analysis initiation• Ionosheperic threat model/monitoring algorithms• Dual frequency multipath limiting antenna

LAAS future TBD based on results of technical, operational, and economic assessments

LAAS StatusLAAS Status


Nationwide Differential (NDGPS)Nationwide Differential (NDGPS)


Five Categories of NDGPS ApplicationsFive Categories of NDGPS ApplicationsFive Categories of NDGPS ApplicationsFive Categories of NDGPS Applications

1. Original Code-Based NDGPS Applications 1 - 3 meters

Navigation, Precision Farming, Positive Train Control, Dredging, Buoy Positioning, Resource Management & GIS

2. Real-Time High Accuracy NDGPS Apps 10-15 centimeters

Real-time Automated Surveying of Roads, Railroads & Harbors; Highway Lane Keeping;Machinery Control; & Auto-Docking of Ships

3. Post-Processing NDGPS Applications 2 - 4 centimeters

Surveying, Mapping, Charting & Hydrography

4. Stationary Scientific NDGPS Applications 2 - 3 millimeters

Plate Tectonics Monitoring & Earthquake Prediction

5. Weather Forecasting Application Water Vapor Info

1. Original Code-Based NDGPS Applications 1 - 3 meters

Navigation, Precision Farming, Positive Train Control, Dredging, Buoy Positioning, Resource Management & GIS

2. Real-Time High Accuracy NDGPS Apps 10-15 centimeters

Real-time Automated Surveying of Roads, Railroads & Harbors; Highway Lane Keeping;Machinery Control; & Auto-Docking of Ships

3. Post-Processing NDGPS Applications 2 - 4 centimeters

Surveying, Mapping, Charting & Hydrography

4. Stationary Scientific NDGPS Applications 2 - 3 millimeters

Plate Tectonics Monitoring & Earthquake Prediction

5. Weather Forecasting Application Water Vapor Info

Categories of Applications Provides


Nationwide DGPS (NDGPS)Nationwide DGPS (NDGPS) StatusStatus

NDGPS expansion is progressing

– 82 sites currently operational - 86 sites by December 2004

Single-station coverage – now 92% of CONUS

– Dual-station coverage currently 50% of CONUS

Nationwide single coverage by end of 2005 with the

addition of 5 more sites

Nationwide dual coverage by end of 2008

– Total of 110 sites in CONUS and 15 sites in Alaska

International Standard used in 40 countries


International StandardInternational Standard

NDGPS is designed to an international, non-proprietary standard– Compliant with RTCM SC-104

and ITU-R M.823

– Increases market for manufacturers

– Enhances Global interoperability

Signal is free to all users 47 other countries operate

systems compatible to ours Resulting in a seamless

international navigation system


Current NDGPS CoverageCurrent NDGPS Coverage


Completed NDGPS CoverageCompleted NDGPS Coverage


Intelligent Transportation SystemsIntelligent Transportation Systems

• Improved roadway safety

– Minimize accidents

• Crash prevention

technologies research

• Road departure prevention

– Electronic mapping

– High-Accuracy NDGPS

• In-vehicle navigation for

precise position

determination

• Snowplow guidance


GPS at Work: Snow Plow VideoGPS at Work: Snow Plow Video


High Accuracy NDGPS Develop a nationwide 3-D dynamic positioning service that

has an accuracy better than 15 centimeter and time to alarm integrity of less than 2 seconds

Coexist with existing NDGPS infrastructure

New Initiatives - AccuracyNew Initiatives - Accuracy

GPS (13-24 meters)

HA-NDGPS Dynamic(0.1 meters)

NDGPS(1 to 3 meters)


HA-NDGPS StatusHA-NDGPS Status

HA-NDGPS Signal Successfully Broadcast from two locations– Static accuracy at 50 km better than 1cm 3-D– Dynamic accuracy at 250 km better than 20 cm 3-D

• Atmospheric Prediction Algorithms show promise

• Implementation Cost <$100,000 per site

• Benefits of multi-site broadcast

• Additional testing planned over next several months


High Accuracy - NDGPS PlansHigh Accuracy - NDGPS Plans

Hawk RunHawk Run

MaconMacon

GradyGrady

HackleburgHackleburg BoboBobo

GoodlandGoodland

TopekaTopeka

OnondagaOnondaga

MedfordMedford

EdinburgEdinburg

MedoraMedora

BillingsBillings

Great FallsGreat Falls

PolsonPolson SpokaneSpokane

AppletonAppleton

Klamath FallsKlamath Falls

AustinAustin

BakersfieldBakersfield

EssexEssex FlagstaffFlagstaff

AlbuquerqueAlbuquerque

SummerfieldSummerfield

PuebloPueblo

HudsonHudson FallsFalls

GWEN Sites New Site Coast Guard Site Green - Operating Red – Planned Dark Blue – HA-NDGPS broadcasting Light Blue – HA-NDGPS planned

Whidbey IsWhidbey Is

Robinson PtRobinson Pt

Fort StevensFort Stevens

Cape Cape MendocinoMendocino

Point BluntPoint Blunt

Pigeon PointPigeon Point

Point ArquelloPoint Arquello

Point LomaPoint Loma

Aransas PassAransas Pass

GalvestonGalveston

English TurnEnglish Turn

MobileMobilePointPoint

Egmont KeyEgmont Key

Key WestKey West

MiamiMiami

Cape CanaveralCape Canaveral

Fort MaconFort Macon

Cape HenryCape Henry

Cape HenlopenCape Henlopen

Sandy HookSandy Hook

MorichesMoriches

PortsmouthPortsmouth

BrunswickBrunswick

Millers FerryMillers Ferry VicksburgVicksburg

MemphisMemphis SallisawSallisaw

KansasKansasCityCity

St LouisSt Louis

RockRockIslandIsland

St. PaulSt. Paul

WisconsinWisconsin Point Point

UpperUpperKeweenawKeweenaw

Whitefish PtWhitefish PtNeebish IslandNeebish IslandCheboyganCheboygan

Sturgeon BaySturgeon Bay

DetroitDetroit

SaginawSaginawBayBay

MilwaukeeMilwaukee

YoungstownYoungstown

TucsonTucson MundayMunday

JacksonJackson

MytonMyton

El PasoEl Paso

INELINEL

DandridgeDandridge

CincinnatiCincinnati

MontereyMonterey

LangtryLangtry

RawlinsRawlins

WeiserWeiser

KanabKanab

HagerstownHagerstown

AshvilleAshville

MartinsvilleMartinsville

MiddleburyMiddlebury

Jack Jack CreekCreek

OdessaOdessa

GreensboroGreensboro

OmahaOmaha

Pine Pine RiverRiver

St. Mary’sSt. Mary’s

LouisvilleLouisville

AcushnetAcushnet

ElmiraElmira

KensingtonKensington

FayettevilleFayettevilleNew BernNew Bern

AnnapolisAnnapolis

Canton Canton

Iowa CityIowa City

St Mary’sSt Mary’s

LedyardLedyard

SenecaSeneca

LincolnLincoln

WenatcheeWenatchee

WhitneyWhitney

ClarkClark

ChicoChico

PenobscotPenobscot

CharlestonCharleston

SavannahSavannah

HartsvilleHartsville

Reedy PointReedy Point

DriverDriver

Pattern Pattern


NDGPS Partner ProjectsNDGPS Partner Projects

Continuously Operating Reference Stations (CORS) Program


NDGPS Partner ProjectsNDGPS Partner Projects (cont.) (cont.)

NOAA’s Forecast Systems Lab ContinuouslyMeasures Water Vapor

NDGPS Site in Whitney, NENDGPS Site in Whitney, NE


NDGPS Partner Projects NDGPS Partner Projects (cont.)(cont.)

University NAVSTAR Consortium (UNAVCO)

NDGPS Site in Pueblo, CONDGPS Site in Pueblo, CO


Loran Developments in the U.S.


Status of Loran in the U.S.Status of Loran in the U.S.

Legacy Loran Today

Loran Modernization – Achievements – Differential Loran

– Loran Data Channel

– Loran Station Electronics

– Control Station Electronics

Loran Modernization – Expectations– Complete Electronics modernization

– Implement Time of Transmission (TOT) control

– Evolve to Enhanced Loran (eLoran) in both CONUS and Alaska


Legacy LoranLegacy Loran

Loran is currently:– A hyperbolic radionavigation system…

• …operating between 90 kHz and 110 kHz…• …that uses a very tall antenna…• …that broadcasts primarily a ground wave• …at high power…• …that provides both lateral position…• …and a robust time and frequency standard

– A supplemental system for enroute aviation navigation in the U.S. National Airspace System (NAS)

– A system for maritime navigation in the coastal confluence zone (CCZ)

– A Stratum 1 frequency standard (i.e., 1 x 10-11) that also provides time within 100 ns of UTC (USNO)


As a radionavigation system, Loran provides:

– A predicted 2drms accuracy of 0.25 nm (460 m) and a repeatable accuracy of 60-300 ft (18-90 m)*

– An availability of 99.7% (based on triad operation)*

– A level of Integrity based on exceeding certain operational parameters measured at the transmitters and at system area monitor sites

– Continuity no greater than 99.7% (its availability), but potentially worse depending on receiver characteristics and geometry of the triad being used…

– Loran today does not meet high-performance, precision standards relative to other Nav aids…

* U.S. Federal Radionavigation Plan (FRP)

Legacy Loran Legacy Loran (cont.)(cont.)


North American Loran SystemNorth American Loran System

New SSX Installed!

George, Washington;

Dana, Indiana; and

Fallon, NV

New TFE also Installed! Baudette, MN; Seneca, NY;

Boise City, OK; Malone, FL; and Havre, MT

TTX Stations: 88 US, 11 Canadian

Control Stations

New SSX Stations:New SSX Stations: 33 US

LSU

SSX Stations: 88 US, 44 Canadian

SSX Stations w/New TFE: 5 USSSX Stations w/New TFE: 5 US


Today’s Coverage in North AmericaToday’s Coverage in North America


“The Government is evaluating the ability of an enhanced Loran system to support non-precision approach for aviation users, harbor entrance and approach for maritime users, and improved performance for time and frequency users.”

“If the Government concludes as a result of the evaluations that Loran-C is not neededis not needed or is not cost is not cost effectiveeffective, the United States Coast Guard (USCG) will plan to disestablish the system by the end of fiscal year 2008 with appropriate public notice.”

Current U.S. Loran PolicyCurrent U.S. Loran Policy


U.S. DOT Navigation Task Force ReportU.S. DOT Navigation Task Force Report

“If Loran can meet

requirements for non-

precision approach for

aviation users, harbor

entrance and approach for

maritime users, and

improved performance for

time and frequency users,

and is cost effective,

Loran should be included in the future radionavigation mix.”


eLoraneLoranLoran-CLoran-C

Loran Technical Evaluation ConclusionsLoran Technical Evaluation Conclusions

“The evaluation shows that the modernized Loran system could satisfy the current NPA, HEA, and timing/frequency requirements in the United States and could be used to mitigate the operational effects of a disruption in GPS services...

“…If the decision is made to retain Loran as one of the federally provided radionavigation systems, the extent to which these modifications are accepted and implemented will define the actual characteristics of the resulting enhanced Loran (eLoran) system.”


Achieving “Enhanced Loran”Achieving “Enhanced Loran”

“Enhanced Loran” means a modernized Loran that meets the current requirements of GPS navigation and timing users and, therefore, can be used as a GPS back-up

Requirements must be met for:– Maritime Harbor Entrance & Approach (HEA)

• Accuracy within 20 meters

– Aviation Non-Precision Approach (NPA)• Probability of Hazardous or Misleading information no greater

than 1 x 10-7 per hour

– Timing• Within 100 nanoseconds of UTC

Enhanced Loran (eLoran) availability:– CONUS by December 31, 2008– Alaska by December 31, 2009


Loran-C vs. Loran-C vs. eLoraneLoran

The Loran technical evaluation showed that eLoran could meet the aviation requirements for non-precision approach (NPA) and the maritime requirements for harbor entrance and approach (HEA)

0.999 - 0.99990.999 - 0.9999over 150 secover 150 sec

0.997

Continuity

0.99999990.9999999(1 x 10-7)(1 x 10-7)0.999 – 0.99990.999 – 0.99990.004 - 0.01 nm0.004 - 0.01 nm

(8 – 20 m)(8 – 20 m)eLoran

10 second alarm/

25 m error0.997

0.25 nm(463 m)Loran-C

IntegrityAvailabilityAccuracy


Loran Data ChannelLoran Data Channel

Loran must transmit information to users to achieve the accuracy, availability, integrity, and continuity requirements for NPA and HEA

eLoran will transmit this information by adding a 9th Pulse to the Loran transmission

It preserves navigation information on pulses 1-8

Its feasibility has been proven with solid-state transmitters

U.S. has successfully tested its ability to broadcast and receive station ID, integrity, time, and differential messages

Facilitates all-in-view vs. chain operation

Each Loran station becomes essentially a pseudolite

U.S. is planning to activate 9th pulse at Loran Station Seneca, NY and perform additional testing in Boston and New York using differential corrections from several monitors


Time of Transmission (TOT) ControlTime of Transmission (TOT) Control

Evolving from the current System Area Monitoring (SAM) control to Time-of-Transmission Control is essential to achieving eLoran All of CONUS should be completed by

December 2005, including:• Loran and Control Station electronics modernized • Loran on Time-of-Transmission control implemented• All-in-view/9th pulse receivers development• Differential Loran information developed for specific

harbors


New Loran Station ElectronicsNew Loran Station Electronics

New Solid State New Solid State Transmitter (NSSX)Transmitter (NSSX)

New Timing & New Timing & Frequency Equipment Frequency Equipment

(NTFE)(NTFE)


New Control-Station ElectronicsNew Control-Station Electronics

New Loran Consolidated Control New Loran Consolidated Control System (NLCCS)System (NLCCS)


Differential Loran – Real WorldDifferential Loran – Real World

Maritime EnvironmentMaritime Environment Shipboard InstallationShipboard Installation


Differential Loran – Real TimeDifferential Loran – Real Time

-10 -8 -6 -4 -2 0 2 4 6 8 10 1221

22

23

24

25

26

27

28

29

30

31

32

Longitude-min re 76W

Latit

ude-

min

re

39N

0 5 10 15 20 25 30 35 40 45 500

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

Horizontal Error - meters

Cum

ulat

ive

dist

ribut

ion

Vessel’s Track LineVessel’s Track Line

Accuracies AchievedAccuracies Achieved


Prototype Loran Card inPrototype Loran Card inMulti-Mode Avionics ReceiverMulti-Mode Avionics Receiver

Rockwell Collins has continued the work on their own to incorporate low cost gyros into the integrated receiver solution

Integrated GPS/LORAN receiver for general aviation is also being developed by FreeFlight Systems and Locus under FAA contract


FreeFlight/LocusFreeFlight/LocusGA Multi-Mode ReceiverGA Multi-Mode Receiver

Phase I Prototype (Two-box initial solution) similar to GPS/WAAS/LORAN Rockwell Collins MMR/Locus development

Phase I Prototype testing of Integrated GPS/WAAS/LORAN receiver testing progressing at this time


Phase II Prototype to become available for testing Spring 2005

FreeFlight/Locus GA Multi-Mode FreeFlight/Locus GA Multi-Mode ReceiverReceiver


Megapulse/Reelektronika/Si-Tek Megapulse/Reelektronika/Si-Tek Multi-Mode Marine ReceiverMulti-Mode Marine Receiver

Front End & ADC77 x 47 mm

Signal Processor

77 x 51 mm

Prototype became available for testing: Spring 2004

Production units expected: Winter 2004

GPS – WAAS


New Loran/GPS/WAAS New Loran/GPS/WAAS Megapulse/Reelektronika ReceiverMegapulse/Reelektronika Receiver

85 mm

110 mm

30 mm


Summary As the global standard for positioning, navigation, and timing, GPSGPS

use continues to grow in all modes of transportation and numerous civil applications

GPSGPS modernization and its augmentations are integral components of the emerging robust and reliable positioning, navigation, and timing (PNT) infrastructure

Modernization of Loran continues as part of the U.S. transportation infrastructure

The decision to continue Loran services in the U.S. is currently under review. A U.S. government decision is pending

GPS augmentations and “eLoran” type systems all have a potential role to play in the radionavigation and positioning mix of the future

Greater PNT capabilities for civil users worldwide Greater PNT capabilities for civil users worldwide


POINT OF CONTACT INFO.

James J. Miller, Deputy DirectorU.S. Department of Transportation, Office of the

SecretaryNavigation & Spectrum Policy, Nassif Bldg.,

Rm. 10223E400 Seventh Street, S.W., Washington, D.C.

20590

(202) 366-5918 [email protected]

gps augmentations and enhanced loran: infrastructure precision and reliability

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