Editing Loran-C (section)

== LORAN Data Channel (LDC) ==
LORAN Data Channel (LDC) is a project underway between the [[Federal Aviation Administration|FAA]] and [[United States Coast Guard]] to send low bit rate data using the LORAN system. Messages to be sent include station identification, absolute time, and position correction messages. In 2001, data similar to [[Wide Area Augmentation System]] (WAAS) [[Global Positioning System|GPS]] correction messages were sent as part of a test of the Alaskan LORAN chain. As of November 2005, test messages using LDC were being broadcast from several U.S. LORAN stations.<ref>{{Cite book|last=Enterprise|first=I. D. G.|url=https://books.google.com/books?id=OXHCuWMYE00C&q=chain.+As+of+November+2005%2C+test+messages+using+LDC+were+being&pg=RA1-PA36|title=Computerworld|date=2005-02-07|publisher=IDG Enterprise|language=en}}</ref>

In recent years, LORAN-C has been used in Europe to send differential GPS and other messages, employing a similar method of transmission known as EUROFIX.<ref>{{Cite book|url=https://books.google.com/books?id=v3JDAQAAIAAJ|title=International Aerospace Abstracts|date=1990|publisher=Technical Information Service, American Institute of Aeronautics and Astronautics|language=en}}</ref>

A system called SPS (Saudi Positioning System), similar to EUROFIX, is in use in Saudi Arabia.<ref>{{Cite web | title=A New Navigation Positioning System run by Saudi Ports Authority  | publisher=Saudi Ports Authority  | year=2006  | url=http://www.ports.gov.sa/section/full_story.cfm?aid=307  | access-date=21 January 2011  | url-status=dead  | archive-url=https://web.archive.org/web/20110210111415/http://www.ports.gov.sa/section/full_story.cfm?aid=307  | archive-date=10 February 2011  | df=dmy
}}</ref> GPS differential corrections and GPS integrity information are added to the LORAN signal. A combined GPS/LORAN receiver is used, and if a GPS fix is not available it automatically switches over to LORAN.