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Terminate Long Range Aids to Navigation (Loran-C) Signal

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U.S. Coast Guard, DHS.




On October 28, 2009, the President signed into law the 2010 Department of Homeland Security Appropriations Act. The Act allows for the termination of the Loran-C system subject to the Coast Guard certifying that termination of the Loran-C signal will not adversely impact the safety of maritime navigation and the Department of Homeland Security certifying that the Loran-C system infrastructure is not needed as a backup to the GPS system or to meet any other Federal navigation requirement. Those certifications were made; and the U.S. Coast Guard will, commencing on or about February 8, 2010, implement plans to terminate the transmission of the Loran-C signal and commence a phased decommissioning of the Loran-C infrastructure. These plans include ending transmissions at 18 Loran stations located in the contiguous United States and 6 Loran stations in Alaska. The Department of Homeland Security anticipates that all Loran stations will cease transmitting the Loran-C signal by October 1, 2010.


Transmission of the Loran-C signal and phased decommissioning of the Loran-C infrastructure will commence on or about February 8, 2010. All Loran stations are expected to cease transmitting the Loran-C signal by October 1, 2010.


To view this notice go to, insert USCG-2009-0299 in the “Keyword” box, and then click “Search.” If you do not have access to the internet, you may view the docket online by visiting the Docket Management Facility in Room W12-140 on the ground floor of the Department of Transportation West Building, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. We have an agreement with the Department of Transportation to use the Docket Management Facility.

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If you have questions on this notice, contact Mr. Mike Sollosi, U.S. Coast Guard, Department of Homeland Security, telephone (202) 372-1545,

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Background and Purpose

The U.S. Loran-C system is a low frequency hyperbolic radionavigation system. A Loran-C receiver measures the slight difference in time it takes for pulsed signals to reach a ship or aircraft from the transmitting stations within a Loran-C chain to develop a navigational position. Loran-C is approved for use in the U.S. Coastal Confluence Zone and as a supplemental air navigation aid. Loran-C is operated and maintained by the U.S. Coast Guard.

The Loran-C system was a valuable position and navigation system when it was established in 1957. As a result of technological advancements over the last 20 years and the emergence of the U.S. Global Positioning System (GPS), Loran-C is no longer required by the armed forces, the transportation sector, or the nation's security interests, and is used only by a small segment of the population.

The Loran-C system was not established as, nor was it intended to be, a viable systemic backup for GPS. Backups to GPS for safety-of-life navigation applications, or other critical applications, can be other radionavigation systems, or operational procedures, or a combination of these systems and procedures. Backups to GPS for timing applications can be a highly accurate crystal oscillator or atomic clock and a communications link to a timing source that is traceable to Coordinated Universal Time.

With respect to transportation to include aviation, commercial maritime, rail, and highway, the Department of Transportation has determined that sufficient alternative navigation aids currently exist in the event of a loss of GPS-based services, and therefore Loran currently is not needed as a back-up navigation aid for transportation safety-of-life users.

The Department of Homeland Security will continue to work with other Federal agencies to look across the critical infrastructure and key resource sectors identified in the National Infrastructure Protection Plan assessment to determine if a single, domestic system is needed as a GPS backup for critical infrastructure applications requiring precise time and frequency. If a single, domestic national system to back up GPS is identified as being necessary, the Department of Homeland Security will complete an analysis of potential backups to GPS. The continued active operation of Loran-C is not necessary to advance this evaluation.

On January 22, 2009 (74 FR 4047), the U.S. Coast Guard began a public review process for its Draft Programmatic Environmental Impact Statement (PEIS), under the National Environmental Policy Act, which evaluated the environmental impacts of several alternatives for the Loran-C system, including termination of the Loran-C signal. The U.S. Coast Guard considered comments received in response to the Draft PEIS and released a Final PEIS on June 12, 2009 (USCG-2007-28046). A public notice will be issued to announce the Record of Decision.

This announcement is for the purpose of informing the public of the Coast Guard's intention to begin termination of the broadcast of the Loran-C signal starting on or about February 8, 2010. All Loran stations will cease transmission by October 1, 2010.

The Department of Transportation was consulted regarding the preparation of this notice. This notice is issued under the authority of 6 U.S.C. 111, 14 U.S.C. 81, and 5 U.S.C. 552.

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Dated: January 4, 2009.

Kevin S. Cook,

Rear Admiral, U.S. Coast Guard, Director of Prevention Policy.

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[FR Doc. 2010-83 Filed 1-6-10; 8:45 am]