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Status – U.S. Maritime Backup Issues

Status – U.S. Maritime Backup Issues. Session 2 , 28 October 2002 Status & Plans of LORAN-C Service Providers 31st Annual Convention & Technical Symposium of the International LORAN Association Crowne Plaza Washington National Airport. Status – U.S. Maritime Backup Issues.

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Status – U.S. Maritime Backup Issues

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  1. Status – U.S. Maritime Backup Issues • Session 2 , 28 October 2002 • Status & Plans of LORAN-C Service Providers 31st Annual Convention & Technical Symposium of the International LORAN Association Crowne Plaza Washington National Airport

  2. Status – U.S. Maritime Backup Issues • FY2002 U.S. LORAN-C Performance • LCDR Max Caruso, USCGNAVCEN Western Operations Officer • Synchronization to UTC • Gene SchlechteNAVCEN Operations Planning Division • Maritime Backup Assessment • CAPT Curtis Dubay, USCGNAVCEN Commanding Officer

  3. FY02 LORAN-C Performance • A year of recapitalization and system modernization

  4. FY02 LORAN-C Performance • LORAN-C Availability Review for the Period 1 October 2001 to 1 October 2002 • The LORAN Operations Information System (LOIS 2 NT) was used to generate this report • LT Bob Berger and CWO Scott McDonald, NAVCEN LORAN Planning Branch provided the data analysis

  5. LOIS DATA GOA 7960 Oct 1, 01 – Oct 1, 02 NC Tok SC PC

  6. NOCUS (8290) UUT by Cause

  7. GLKS (8970) UUT by Cause

  8. SOCUS (9610) UUT by Cause

  9. USWC (9940) UUT by Cause

  10. NEUS (9960) UUT by Cause

  11. NORPAC (9990) UUT by Cause

  12. FY02 LORAN-C AVAILABILITY

  13. FY02 AVAILABILITY(less AUTM)

  14. FY02 AVAILABILITY(less AUTM & Solar)

  15. Status – U.S. Maritime Backup Issues • FY2002 U.S. LORAN-C Performance • LCDR Max Caruso, USCGNAVCEN Western Operations Officer • Synchronization to UTC • Gene SchlechteNAVCEN Operations Planning Division • Maritime Backup Assessment • CAPT Curtis Dubay, USCGNAVCEN Commanding Officer

  16. LORAN Synchronization to UTC • Time Of Transmission Measurement (TOTM) Project started at LSU in late 1990s • 1997 - TOTM equipment installed at Williams Lake • Now - TTM installed at every US Master including the two in Alaska.

  17. LORAN Synchronization to UTC • US Public Law 100-223, Section 310 requires the control the transmission of LORAN signals to within +/- 100 nanoseconds of UTC at times of coincidence (TOC). • The Coast Guard has worked with USNO to steer LORAN transmissions to UTC • USNO monitors & measures LORAN time differences (TD) in far field to determine difference between LORAN Chain & UTC

  18. North American Loran-C System PORT CLARENCE ALEXANDROVSK, RUSSIA GALENA TOK FAIRBANKS ST. PAUL PETROPAVLOVSK, RUSSIA NARROW CAPE SPRUCE CAPE JUNEAU ATTU SHOAL COVE WILLIAMS LAKE COLD BAY FOX HARBOR ST. ANTHONY PORT HARDY COMFORT COVE SAND SPIT BAUDETTE CARIBOU SPOKANE LUMSDEN HAVRE WHIDBEY ISLAND MONTAGUE GEORGE MEDICAL LAKE BISMARK DUNBAR FOREST CAPE RACE CONTROL SITE GREAT FALLS GILLETE CAPE ELIZABETH SENECA TRANSMITTER STATION NANTUCKET MIDDLETOWN DANA PT. CABRILLO PLUMBROOK FALLON PCMS SITE GRAND JUNCTION LSU SANDY HOOK BOISE CITY USNO Monitor NAVCENDET NAVCEN PETALUMA ALEXANDRIA PT. PINOS LITTLE ROCK SEARCHLIGHT CAROLINA BEACH GRANGEVILLE MIDLAND LAS CRUCES MALONE DESTIN MAYPORT NEW ORLEANS RAYMONDVILLE JUPITER INLET

  19. Time of Transmission System • Provides a means to monitor Loran transmissions directly at the transmitting antenna. • Eliminates propagation path uncertainties making +/- 100 nanosecond control possible

  20. GPS Time Time of Transmission System Cesium at Master stations UTC at USNO

  21. TTM Installation at Master Station

  22. SOCUS (9610) TTM Data Plot 15JUL -13OCT 2002

  23. SOCUS (9610) TTM Log Sheet

  24. NEUS (9960) TTM Data Plot 15JUL -13OCT 2002

  25. NEUS (9960) TTM Data Plot 15JUL -13OCT 2002

  26. = T2 Raw Data Avg + T1 Cal - Pulse Tracking Point - Cable Delays (all in nanoseconds) TTM = ( 5108.6631+ 27088.251 - 30000 - 112 ) = 2085 nanoseconds TTM TTM Calculation • TTM Formula for USCG installation: • Sample TTM Calculation for NEUS (9960) on 13 October 2002:

  27. Summary of UTC Measured Offsets • The following offsets have been established utilizing the installed TTM equipment: • NOCUS (8290-M): +2.3 usec • NORPAC (9990-M): +2.5 usec • SOCUS (9610-M): +1.8 usec • USWC (9940-M): +1.3 usec • GOA (7960-M): +1.2 usec • GLKS (8970-M): -0.4 usec • SEUS (7980- M): +0.1 usec • NEUS (9960-M): +0.02 usec

  28. Plan to Remove LORAN UTC Offsets • NAVCEN is planning to time step one chain per week • starting with the West Coast Chains • then East coast chains • last will be the two Alaskan chains • We will send advance user notice before a Chain time step • We Plan to insert one time step for each chain on a Tuesday at 0900 Local time • The time step amount (in microseconds) will be included in the user notice • This process is considered to be the least problematic for the timing/legacy user.

  29. USCG LORAN TTM Contacts • Navigation Center (Operations Planning) • LT Bob Berger, RBerger@navcen.uscg.mil • LORAN Support Unit (Technical) • Mike Campbell, MCampbell@lsu.uscg.mil • Program Manager’s Staff (Policy) • LCDR John Merrill, JMerrill@comdt.uscg.mil

  30. Status – U.S. Maritime Backup Issues • FY2002 U.S. LORAN-C Performance • LCDR Max Caruso, USCGNAVCEN Western Operations Officer • Synchronization to UTC • Gene SchlechteNAVCEN Operations Planning Division • Maritime Backup Assessment • CAPT Curtis Dubay, USCGNAVCEN Commanding Officer

  31. Maritime Assessment • Volpe Study shows vulnerability of GPS • Maritime modes concur • Current infrastructure satisfactory • E-navigation poses growing vulnerability

  32. Maritime Assessment • Future vision – “System of systems” that incorporates adequate backups • Conventional navigation capability, • Regulatory procedures, • Development of alternate “e-inputs”

  33. Maritime Assessment • Two Safety Critical Applications • Harbor, harbor approach, and constricted waterways • Total reliance on DGPS is a concern • Automatic Identification System (AIS) • Positioning and timing are concerns

  34. Maritime Assessment • Comments on Study Recommendations • Continue LORAN-C modernization • Assess capabilities of “enhanced LORAN” • Certification of GPS receivers • By July 2002, a maritime certification program will be in place under SOLAS • USCG participation in domestic and international standards setting bodies

  35. Maritime Assessment • Backup System Initiatives • Leverage FAA’s LNAV LORAN study • Partner with industry to analyze enhanced LORAN capabilities • Develop & assess integrated maritime receiver technology

  36. Status – U.S. Maritime Backup Issues • Session 2 , 28 October 2002 • Status & Plans of LORAN-C Service Providers 31st Annual Convention & Technical Symposium of the International LORAN Association Crowne Plaza Washington National Airport

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