international loran association conference boulder, colorado 4 november 2003
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Ongoing Loran Evaluations at the Federal Aviation Administration and the US Coast Guard Mitchell J. Narins Systems Engineer Federal Aviation Administration Navigation Integrated Product Team. International Loran Association Conference Boulder, Colorado 4 November 2003. - PowerPoint PPT PresentationTRANSCRIPT
Ongoing Loran Evaluations at theFederal Aviation Administration and theUS Coast Guard Mitchell J. NarinsSystems EngineerFederal Aviation AdministrationNavigation Integrated Product Team
International Loran Association Conference
Boulder, Colorado4 November 2003
2
Purpose of the Evaluations
To determine whether an enhanced Loran system can provide the:
AccuracyAvailabilityIntegrityContinuity
a) to support Lateral Navigation through all phases of flight – including Non-Precision Approach (NPA)
b) to support Harbor Entrance and Approach (HEA) for maritime users
To determine what other ancillary benefits can be derived from the continued provision of enhanced Loran services
e.g., to support Stratum 1 timing and frequency users
To determine if providing these services via Loran is cost-beneficial (i.e., Benefits/Costs >1)
3
North American Loran System
TTX Stations: 11 US, 1 Canadian
SSX Stations: 13 US, 4 Canadian
LSU Control Stations
New SSX Stations: 1 US
First New SSX Station Installation
George, Washington
4
GovernmentFAA
Navigation and Landing Systems Engr, AND-740 Navigation and Landing System Architecture, ASD-140 CNS Test and Evaluation, ACB-440 Flight Standards, AFS-400 Aircraft Certification, AIR-130 Special Programs, AVN-5
US Coast Guard HQ Aids to Navigation Navigation Center Loran Support Unit Command and Control Center
Volpe National Transportation System Center
Program Participants
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Program ParticipantsIndustry
Booz|Allen|Hamilton
Free Flight Systems*
Illgen Simulation Technologies, Inc.
JJMA
Locus, Inc.
Megapulse, Inc.
Peterson Integrated Geopositioning
Reelektronika*
Rockwell Collins
Timing Solutions
Si-Tex Marine*
WR Systems
AcademiaOhio University
Stanford University
US Coast Guard Academy
University of Rhode Island
University of Alaska
University of Wales*
*New FY 2003 Team Member
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Loran Program Logo Collection
Booz|Allen|Hamilton
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Team Contributions to ILA 2003
4 November:Loran Integrity Certification
Dr. Per Enge, Stanford University
Loran of the 21st Century CAPT Tom Gunther (USCG Ret.), Booz|Allen|Hamilton
Loran-C Maintenance Support CDR John Macaluso, Loran Support Unit
The Challenge of Finding Your Way in a World Hostile to Radio Navigation
Dr. Durk Van Willigan
On-air with the New Solid State Transmitter CDR Chuck Teaney (USCG Ret.) WR Systems
The Case for Transitioning to Time of Emission Control in the US
CAPT Curt Dubay, USCG Navigation Center
Loran Operation Performance Report LCDR Max Caruso, USCG NavCen Detachment
Supporting the Enhanced Loran-C System LT (jg) Zach Conover, Loran Support Unit
Applications of Differential Loran CDR Doug Taggert (USCG Ret.), Overlook Systems
Differential Loran CAPT Ben Peterson (USCG Ret.), Peterson Integrated
Geopositioning
Common-View LORAN-C for Precision Time and Frequency Recovery
Dr. Tom Celano, Timing Solutions Corporation
Predicted Differential Loran Performance in Boston Harbor Mr. Andre Grebnev, Megapulse, Inc.
5 November:Early Skywave Propagation
Dr. Peter Morris, Northrup Grumman
Early Skywave Examples from PCMS Data CAPT Bob Wenzel (USCG Ret.), Booz|Allen|Hamilton
Mitigation of the Effects of Early Skywave CAPT Ben Peterson (USCG Ret.), PIG
Getting a Bearing of ASF Directional Corrections CAPT Dick Hartnett, USCG Academy
Modelling Loran-C Envelope-to-Cycle Differences in Mountainous Terrain
Dr. David Last, University of Wales – Bangor
Summer Vacation 2003 – ASF Spatial Mapping in CO/AR/FL/CA Mr. Greg Johnson, JJMA
Analysis of Groundwave Propagation Effects for Loran RNP 0.3 Dr. Sherman Lo, Stanford University
6 NovemberLoran-C Band Data Collection Efforts at Ohio University
Mr. Curt Cutright, Ohio University
Atmospheric Noise Analysis Mr. Lee Boyce, Stanford University
FAA Tests and H-Field Antenna to Increase Loran-C Availability During P-Static
Mr. Robert Erikson, FAA Technical Center
Integrated GPS/Loran Navigation Sensor for Aviation Applications Mr. James Doty, Rockwell Collins
Development of an Integrated GPS/LORAN Prototype Navigation System for Business and General Aviation Applications
Dr. James Davis, Free Flight Systems
Integrated GPS/ Loran Sensor for Maritime Operations Mr. Wouter Pelgrum, Reelektronika
On Non-iterative Loran-C Time Difference to Latitude/Longitude Converters
Dr. Paul Williams, University of Wales - Bangor
The U.S. Loran-C Evaluation Program has much to be proud of…and equally much to report out at this ILA Conference:
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Loran-C Evaluation Program
FY 1994Federal Radionavigation Plan (FRP) announced that Loran-C service would terminate 31 December 2000Congressional lobbying (primarily by aviation groups) resulted in budgetary language to continue system development
FY 1997 ($4.6 M)Congressional Mandate
The FY 1997 Congressional budget provided funds to the FAA for “upgrades to the Loran-C navigation system and... to implement an automatic blink system (ABS).”
FY 1998 ($3 M)Congressional Mandate
The FY 1998 Congressional budget directed the FAA “to continue Loran-C upgrades initiated in fiscal 97.”
FY 1999 ($7 M)Congressional Mandate
The Congressional budget provided funds to the FAA for “further development of the Loran-C navigation system.”
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Loran-C Evaluation Program
FY 2000 ($10 M)Congressional Mandate
The Congressional budget provided funds to the FAA for “further development of the Loran-C navigation system.”
FY 2001 ($20 M requested, $25 M provided)First year included in President’s budget
FY 2002 ($13 M requested, $19 M provided)
FY 2003 ($13 M requested, $25 M provided)
FY 2004 ($0 requested, $20M - $25M expected)Senate (Appropriations Report) raised the level of funding to $20 Million
House (Appropriations Report) raised the level of funding to $25 Million
Awaiting Conference Decision
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A Most Substantial Investment
U.S. Loran Evaluation Program Cumulative Expenditures
FY 97 - FY 04
0
20
40
60
80
100
120
140
97 98 99 00 01 02 03 04
Fiscal Year
Do
lla
rs (
mil
lio
ns
) *
*Assumes $25 M in FY 04
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Current US Loran-C Policy
“While the Administration continues to evaluate the long-term need for continuation of the Loran-C radionavigation system, the Government will operate the Loran-C system in the short term. The U.S. Government will give users reasonable notice if it concludes that Loran-C is not needed or is not cost effective, so that users will have the opportunity to transition to alternative navigation aids. With this continued sustainment of the Loran-C service, users will be able to realize additional benefits. Improvement of GPS time synchronization of the Loran-C chains and the use of digital receivers may support improved accuracy and coverage of the service. Loran-C will continue to provide a supplemental means of navigation. Current Loran-C receivers do not support nonprecision instrument approach operations.”
2001 US Federal Radionavigation Plan
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Volpe GPS Vulnerability Study
The vulnerability study released on 10 September 2001 recognized the potential for Loran-C to be a robust backup system for GPS navigation and augmentation and timing.
“In an effort to provide the greatest benefit to the users, encourage the development of affordable vehicle-based backup such as GPS/inertial receivers, and, in the event Loran-C becomes a viable terrestrial backups to GPS, aviation certifiable Loran-C receivers, and GPS/Loran-C receivers.”
“Conduct a comprehensive analysis of GPS backup navigation and precise timing options including VOR/DME, ILS, Loran-C, inertial navigation systems, and operating systems.
“Continue the Loran-C modernization program of the FAA and USCG, until it is determined whether Loran-C has a role as a GPS backup system. If it is determined that Loran-C has a role in the future navigation mix, DOT should promptly announce this to encourage the electronics manufacturing community to develop new Loran-C technologies.”
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Loran’s Potential as a GPS Backup Parameter Loran GPS
Frequency 100 kHz 1.2-1.5 GHz
Propagation Groundwave Line of Sight
Chief Propagation Errors Conductivity, troposphere Iono delay variations*
variations
Penetration Walls, ground, 6' seawater Very little penetration
Modulation TD + CD Spread spectrum CD
Coverage To ground level To ground level
Signal Strength Relatively high Very low by design
Timing Basis Triple Cesium Rubidium at present
Tx Location Ground - stationary Space - moving
Utility: Aviation example En route, terminal airspace En route, terminal airspace Lateral-guided approach Lateral-vertical approach**
User communities Multiple (air, land, marine) Multiple ( air, land, marine)
* Propagation errors are affected at different times and places by components of solar storms
* GPS propagation variations are not correlated with Loran-C propagation errors.
** Vertical-guided "precision" approaches require WAAS or LAAS augmentations.
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Loran-C Navigation Current Capabilities/Future Needs*
Accuracy Availability Integrity Continuity
Current Definition of Capability * (FRP)
0.25 nm
(463 m)0.997
10 second alarm/
25m error0.997
FAA NPA (RNP.3) Requirements
0.16 nm
(307 m)0.999 – 0.9999 0.9999999 0.999 - 0.9999
USCG Harbor Requirements
(to date)
0.004 - 0.01 nm
(8 – 20 m)0.997 - 0.999
10 second alarm/
25m error
0.9985 – 0.9997 over 3 hours
Note: Most stringent requirements shown in aviation orange.
* Includes Stratum 1 timing and frequency capability.
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Timing User Spectrum
0.1 ns 1 ns 10 ns 100 ns 1 µs 10 µs 100 µs 1 ms 10 ms 100 ms 1 s
PTTI/R&D- NIF
Scientific/Experimental
High Precision Military- GPS Monitor Stations- GPS Weapons- AT3 Airborne Geolocation Demo- Bistatic Radar- Other Applications
Advanced Comms
Power Systems- Fault Location- Phasor Meas- Data Sharing
CDMA2000- Base Stations
Low Precision Military- Ground Terminals- VHF Special Comms
Astronomy
Financial Transactions
National Timing Labs
Wide Area Data Logging- Seismic monitoring- Nuclear Blast Detection
Digital Time Servers- NTP, etc
Authentication- Internet login
Could be served by Enhanced LORAN (eLoran)
Timing user survey not intended to be a complete representation of all users. Requirements have been generalized and averaged over user groups
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Frequency User Range
10-15
VLBI
High Precision Military- GPS Monitor Stations- Various Applications
Stratum 1 Comms- Telcos- Military GT- Digital Wideband
Low Precision Metrology
- Equipment Calibration
CDMA2000- Base Stations
Low Precision Military- Combat Control Systems
Misc- Broadcast TV- Digital Modular
Radio- IEEE P802.16
Wireless
10-14 10-13 10-12 10-11 10-10 10-9 10-8 10-7 10-6 10-5
Oscillator Manufacturers- Cal of low-cost xtal
Could be served by eLORAN
High Precision Metrology
- Equipment Calibration
National Timing Labs
Frequency user survey not intended to be a complete representation of all users. Requirements have been generalized and averaged over user groups
Status of the
Ongoing Loran Evaluation and
Associated System Recapitalization
Final Report due to the Departments of Transportation and Homeland SecurityMarch 2004
AccuracyAvailability
IntegrityContinuity
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Loran Evaluation Activities
To determine Loran Accuracy Potential:ASF* studies and calibration (for both conductivity and terrain)Receiver/Integrated receiver studiesLoran Accuracy Performance Panel (LORAPP)Differential Loran study
To determine Loran Availability Potential:H-Field Antenna/P-static testingCONUS All-in-view receiver analysisNoise analysisSSX and TFE modification evaluations
To determine Loran Integrity Potential:Loran Integrity Performance Panel (LORIPP) Time of Transmission/ASF studies
To determine Loran Continuity Potential:Receiver/Integrated receiver/antenna studies
*additional secondary factors
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Loran Issue 1: Accuracy
Current Accuracy: 0.25 nm, 2drms, 95%
Target Accuracy (NPA): 0.16 nm (307 m) - RNP 0.3
0.43 nm (802 m) - RNP 0.5
Target Accuracy (HEA): 8 – 20 m, 2drms, 95%
Issues Potential MitigationsOld timing sources New cesium clocks
Old timing equipment New timing suite
Tube technology Solid State Transmitter (SSX) technology
Simple propagation model New ASF* tables/algorithms
No real-time corrections LORAPP (Differential Loran)
*additional secondary factors
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Flights to Support Characterization of ASFsAugust 2002 and March 2003
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Typical Results
Loran 7
Loran 1 GPS 1
Loran 8GPS 7
GPS 8
~13.0 m~3.0 m
~2.0 m
Loran 2
Loran 7
GPS 2Loran 3GPS 7
GPS 3
~9.0 m
~6.0 m
~6.5 m
NPA Requirement: 307 m!
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Flights to Support Characterization of ASFs July – September 2003
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Loran ASF Measurement CampaignLots of Miles – Lots of Data
Monterey, California Pensacola/Destin, Florida
Grand Junction, Colorado Little Rock, Arkansas
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Loran Issue 2: Availability
Current Availability: 0.997
Target Availability (NPA): 0.999 - 0.9999
Target Availability (HEA): 0.997 – 0.999
Issues Potential MitigationsPrecipitation Static H-Field Antenna*
Atmospheric Noise H-Field, AIV Receiver
Loss of Station Power UPS
Lightning New Lightning Protection
Chain/Stick Availability All-in-view receivers
Tube overloads Solid State Transmitters
*Awaiting safety certification
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Loran Issue 3: Integrity
Current Integrity: 10 sec. alert @ + 100ns or other specified error conditions
Target Integrity (NPA): 0.9999999*
556m HPL, 10 sec. alert
Target Integrity (HEA): 0.99997**
Issues Potential MitigationsPresumed Integrity/ Loran Integrity Panel (LORIPP)Auto Blink System Loran Accuracy Panel (LORAPP)
*For Aviation: The probability of providing Hazardous or Misleading Information (HMI) is 1 x 10-7
**For Maritime: The probability of providing Hazardous or Misleading Information (HMI) is 3 x 10-5
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Loran Issue 4: Continuity
Current Continuity: 0.997
Target Continuity (NPA): 0.999 - 0.9999
Target Continuity (HEA): 0.9985 – 0.9997
Issues Potential MitigationsSame as Availability plus:
Receiver acquisition time New DSP technology
New SSX Switch Units
AIV/Integrated Receiver
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Prototype Brassboard Locus Loran Card Installed in Rockwell Collins Multi-Mode Receiver
Flight Testing Results will be reported out on Thursday
Integrated GPS/Loran receiver for general aviation also being developed by Free Flight Systems and Locus
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FreeFlight/Locus GA Multi-Mode Receiver
Similar to GPS/WAAS/Loran MMR development
Phase I Prototype testing of Integrated GPS/WAAS/Loran receiver testing to commence this fall
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FreeFlight/Locus GA Multi-Mode Receiver
Phase II Prototype to be available for testing Spring 2004
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Megapulse/Reelektronika/Si-TekMulti-Mode Marine Receiver
Front End & ADC77 x 47 mm
Signal Processor
77 x 51 mm
The Loran Decision Process
Final Report due to the Departments of Transportation and Homeland SecurityMarch 2004
What are we doing?When are we doing it?
When will we be finished?When will there be a decision?
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The Loran Decision Process
1. Determine if Loran can provide the accuracy, availability, integrity, and continuity to support non-precision approach for aviation and harbor entrance and approach for maritime.
2. Determine if Loran can provide benefits to timing and frequency users.
3. Determine if Loran can provide navigation, timing, and frequency benefits in a cost effective manner (i.e., B/C >1.0).
4. Review results of evaluation and make recommendation to Secretary of Transportation.
5. Announce US Gov’t Decision regarding future of Loran.
1. Loran Evaluation Team will provide report to the Department of Transportation NLT 31 March 2004.
2. Loran Evaluation Team will provide report to the Department of Transportation NLT 31 March 2004.
3. Loran Evaluation Team will provide report to the Department of Transportation NLT 31 March 2004.
4. Positioning and Navigation (PosNav) Committee of the Department of Transportation
5. Secretary of Transportation
Action Responsibility
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The Loran Decision Process
Loran Evaluation Team compiles technical
findings and BCA Data into Draft Report
December 2003
LORIPP LORAPP
Volpe FAATC
Internal FAA Review
Internal USCG Review
Loran Evaluation Team compiles comments
into Final Report
March 2004
PosNav Committee members review the
report
PosNav Committee meets to discuss report findings and determine what recommendation should be forwarded to
The Secretary of Transportation
Department of Homeland Security
PosNav Committee recommends decision
to SecDOT
Secretary of Transportation
Announces Decision
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Department of Transportation Pos/Nav Committee
Hon. Jeffrey Shane, Undersecretary of Transportation for Policy, ChairmanMembers
Federal Aviation AdministrationFederal Highway AdministrationFederal Motor Carrier Safety AdministrationFederal Railroad AdministrationFederal Transit AdministrationMaritime AdministrationNational Highway Traffic Safety AdministrationSaint Lawrence Seaway Development CorporationSurface Transportation BoardResearch and Special Programs AdministrationUS Coast GuardUS Department of Commerce (Geodetic Survey/Weather/Time)US Department of DefenseUS Department of Homeland Security (?)
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SummaryFY ’03 – Team continued its excellent progressFY ’04 – Work continues:
Development of multi-mode receivers for aviation and maritime usersDevelopment of ASF models that include spatial factors based on both conductivity and terrain factors and temporal factors based on multiple seasonal measurements to support NPADesign and development of differential Loran system and means to transmit ASF “corrections” to users to support HEATest of Differential LoranCompletion of timing and frequency testing to determine potential level of support to user communitiesCompletion of Benefit/Cost AnalysisCompletion of p-static testingCompletion of LORIPP and LORAPP activitiesPublication of evaluation reportUS Government Loran Decision
Questions
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Aviation Requirements: RNP* 0.3 (target); RNP* 0.5 (minimum)
Performance Requirement Value
Accuracy (target) 307 metersAccuracy (minimum) 802 meters
Alarm Limit (target) 556 metersAlarm Limit (minimum) 926 meters
Integrity 10-7/hour
Time-to-alarm 10 seconds
Availability (minimum) 99.9%Availability (target) 99.99%
Continuity (minimum) 99.9%Continuity (target) 99.99%
(Source: FAA Loran Evaluation Report, June 2002)
*Required Navigation Performance
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Marine HEA Requirements (Primary)
Performance Requirement Value
Accuracy (target) 10 meters, 95%Accuracy (threshold) 20 meters, 95%
Alarm Limit (target) 25 metersAlarm Limit (threshold) 50 meters
Integrity (target) 3x10-5
Time-to-alarm 10 seconds
Availability (threshold) 99.7%Availability (target/VTS) 99.9%
Continuity (threshold) 99.85% over 3 hours
Continuity (target) 99.97% over 3 hours
(Sources: FRP, DOT Task Force, TASC DGPS Mission Needs Analysis: Harbor Entrance and Approach, IMO Resolutions A.815(19) and draft revisions to A.860(20))
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Marine HEA Requirements (Backup)
Performance Requirement Value
Accuracy (backup) 20 meters, 95%
Alarm Limit (backup) 50 meters
Integrity (target) 3x10-5
Time-to-alarm 10 seconds
Availability (minimum) 99.7%
Continuity (minimum) 99.85% (over 3 hours)
(Sources: FRP, DOT Task Force, TASC DGPS Mission Needs Analysis: Harbor Entrance and Approach, IMO Resolutions A.815(19) and draft revisions to A.860(20))
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Performance Specification Value
Frequency Accuracy (threshold) 1 in 1012 (averaged over 24 hrs)
No External Antenna (desired)
Backward Compatibility (desired)
Integrity Data Minimum of USE/NO USE Flag
Higher Accuracy Time of Day Time Tag (Year/DOY/Second)
Leap Second information
Timing Accuracy <100nsec
Differential Data Daily Correction
(Source: DOT Task Force, T1X1 letter of Oct 2002)
Timing and Frequency Specifications