The U.S. Department of Homeland Security will begin implementing an independent national positioning, navigation and timing system that complements the
Global Positioning System (GPS) in the event of an outage or disruption in service.
The enhanced Loran, or eLoran, system will be a land-based, independent system and will mitigate any safety, security, or economic effects of a GPS outage or disruption. The eLoran system will be an enhanced and modernized version of Loran-C, long used by mariners and aviators and originally developed for civil marine use in coastal areas.
In addition to providing backup coverage, the signal strength and penetration capability of eLoran will provide support to first responders and other operators in environments
that GPS cannot support, such as under heavy foliage, in some underground areas, and in dense high-rise structures. The system will use modernized transmitting stations and an
upgraded network.