The Game Plan for Loran-C Modernization

John J. MacalusoU. S. Coast Guard

Mitchell J. NarinsU. S. Federal Aviation Administration

International Loran AssociationBoulder, Colorado

November 4, 2003

Introduction

• Purpose of Loran-C Modernization

• Overall Enhanced-Loran Context

• Loran Recapitalization Project– Status– Plans (Order of Lorsta Conversion)– Modernized Coverage in 2004

Purpose of Loran-C Modernization

• GPS and GPS augmentation services

• Volpe Vulnerability Study, 1998-2001– Timing, multimodal transportation– Intentional and unintentional interference– Consequences of loss of GPS– Mitigation strategies & technologies

• Loran-C has potential as GPS back-up

Potential of Loran-C

• Loran-C and GPS are complementary

• Both provide timing, positioning & nav info

• GPS is worldwide

• Loran-C operates where concerns are greatest

• Different strengths & weaknesses

• Loran-C requires modernization

“Enhanced Loran”

• Antenna technology• Blink• Communications using the Loran signal• Differential Loran• Early skywave & other integrity issues• Time-of-Transmission Control• Calibration of Loran System• Loran Recapitalization Project

Loran Recapitalization Project

• 24 Coast Guard-operated Lorstas• CONUS & Alaska Lorstas operating

– Vacuum-tube transmitters (TTX)– Solid State transmitters (Legacy-SSX)– Control & Monitoring System (LCCS)

• New Equipment– Solid State Transmitter (NSSX)– Timing & Frequency Equipment (TFE)– Control & Monitoring Equipment (NLCCS)

Paths to Modernization

• Legacy-SSX Lorsta Conversion (13 each)– Install new TFE & integrate with Legacy SSX

• Vacuum-tube Lorsta Conversion (11 each)– Construct new transmitter building– Build/install new transmitter (NSSX)– Install new TFE

• Control Station (2 each)– Install new LCCS at Navcen East & West

First Modernized Lorsta

• Lorsta George, WA– Vacuum-tube transmitter– Converted to NSSX on 23 Oct 2003– Casualty - reverted to TTX on 29 Oct 2003– Troubleshooting currently underway

• Signal can be monitored by NIST, TSC

• Involves Canadian government early

Expected Coverage of Lorsta George

-0.5

0

0.5

1

1.5

-130 -120 -110 -100 -90 -80 -70 -6025

30

35

40

45

50

55

60Number of stations above 45 dB re 1uv/m

+ George

Coverage Adding Dana, Seneca, Baudette

-0.5

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

-130 -120 -110 -100 -90 -80 -70 -6025

30

35

40

45

50

55

60Number of stations above 45 dB re 1uv/m

+ George + Baudette

+ Dana

+ Seneca

Coverage Adding Malone & Boise City

0

1

2

3

4

5

6

-130 -120 -110 -100 -90 -80 -70 -6025

30

35

40

45

50

55

60Number of stations above 45 dB re 1uv/m

+ George + Baudette

+ Dana

+ Seneca

+ Malone

+ Boise City

Chain-by-Chain Conversion

• Great Lakes Chain (GLKS)• US West Coast Chain (USWC)• Northeast US Chain (NEUS)• Southeast US Chain (SEUS)• South Central US Chain (SOCUS)• North Central US Chain (NOCUS)• Gulf of Alaska Chain (GOA)• North Pacific Chain (NORPAC)

Conclusion

• Lorsta George – First converted Lorsta

• GLKS – First converted Loran chain

• Chain-by-chain conversion– CONUS Lorstas– Alaskan Lorstas

• Several other “Enhanced Loran” initiatives

• Loran-C positioned to serve the nation

Questions

John J. MacalusoUSCG Loran Support Unit

(609)523-7248

Mitchell J. NarinsU. S. Federal Aviation Administration

(202)493-4336