Extensively used low-frequency, high-power terrestrial navigation system
Might be phased out in favor of GPS, which is microwave-frequency, low power, and satellite
Might be modernized to complement GPS
24 USCG U.S. LORAN-C stations work in
partnership with Canadian and Russian stations to provide coverage in
Canadian waters and in the Bering Sea.
LORAN-C TD lines on P-Sea plot
Operational characteristics on the boat
LORAN-C provides better than 0.25
nautical mile absolute accuracy for suitably equipped users within the
published areas. Users can return to previously determined positions
with an accuracy of 50 meters or better using LORAN-C in the time
difference repeatable mode.
Some chartplotters can use LORAN instead of GPS, or combine the two for greater accuracy
LORAN receivers usually have NMEA 0183 output
When the Global Positioning System (GPS)
appeared in the1980s, with its positioning accuracy of tens of meters,
many began to regard Loran-C as irrelevant. But others saw it as an
essential source of position and time that could still be relied upon
if GPS failed.
Joint use of LORAN and GPS
An advanced LORAN system can complement GPS
There are budget wars; some want to shut down LORAN and use just GPS.
eLoran is seen both as a complement and backup to GPS.
More accurate than LORAN-C with same or better accuracy
Precise enough to bring ships into harbor in low visibility
Like GPS, a source of precision time and frequency reference
Technically different enough from GPS that environmental conditions, or sabotage, unlikely to affect both
High power transmission allows cheap receivers, even in the same box as GPS.
Will do some things GPS can't, such as acting as a static compass