January 12, 2010
By Sarah Brown
The U.S. Coast Guard gave notice Jan. 7 that it will start decommissioning the long range navigation (loran-C) system beginning Feb. 8.
All loran stations will cease transmission by Oct. 1, according to the notice. While loran-C is not now widely used for navigation, government and independent agencies have recommended using an enhanced version of it, eLoran, as a national backup system for GPS. The termination of loran will leave the country without a single national backup system in the event of a GPS outage.
“Recent reports have shown that the constellation of satellites is vulnerable to outages and service disruptions,” said Craig Spence, AOPA vice president of operations and international affairs. “AOPA has long cautioned against decommissioning loran before a separate navigation system is established as a backup.”
The vulnerability of satellite coverage was made clear in 2007, when a scheduled Navy training exercise in the Port of San Diego unintentionally jammed GPS signals, shutting down satellite-based navigation, tracking, and cell phone services. Outages could become more frequent as older satellites reach the end of their operational life: A Government Accountability Office (GAO) report released in 2009 concluded that many of the older satellites in use could stop working faster than they can be replenished, possibly resulting in reductions in service as early as this year.
In the event of a loss of GPS-based services, the Coast Guard says that the Department of Transportation (DOT) has determined that sufficient alternative navigation aids currently exist and that loran is not needed. However, a 2006 Independent Assessment Team (IAT) report commissioned by the DOT and Department of Homeland Security (DHS) found that “eLoran is the only cost-effective backup for national needs … . It is a seamless backup, and its use will deter threats to U.S. national and economic security by disrupting (jamming) GPS reception.” IAT reiterated its support of eLoran in 2009.
The DOT and DHS jointly recommended in 2007 that eLoran be the national backup for GPS, and DHS formally announced in February 2008 its intention to implement eLoran as a national positioning, navigation, and timing system to complement GPS in the event of an outage or disruption in service.
Loran-C has been periodically slashed from budgets over the past several years, but it has always been restored pending a decision on what system will be in place if satellite services are disrupted. Decommissioning loran-C would eliminate the infrastructure upon which a potential eLoran system would rely.
The 2010 Department of Homeland Security Appropriations Act, signed into law in October 2009, allows for the termination of the system subject to the Coast Guard certifying that termination of the signal will not adversely impact the safety of maritime navigation and DHS certifying that the infrastructure is not needed as a backup to GPS or to meet any other federal navigation requirement. The Coast Guard determined that those certifications were made.
According to the Office of Management and Budget, shutting down loran-C will save $36 million in fiscal 2010 and $190 million over five years.
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