Garmin 378 Manuale Proprietario

LORAN C is a radio navigation aid operated and maintained in the 

United States by the United States Coast Guard. LORAN  

(LOng RAnge Navigation) system covers the entire United States 

and the U.S. Coastal Confluence Zone. From the perspective of a 

mariner, the system is used for ocean and coastal navigation. It can 

be used as a supplemental system for harbor and harbor approach 

navigation, and it is used for inland navigation by recreational 

vehicles. 

The LORAN TD (Time Delay) feature eases the transition from 

using LORAN to using GPS. The GPSMAP unit automatically 

converts GPS coordinates to LORAN TDs for those who have a 

collection of LORAN fixes for favorite fishing spots and other 

waypoints recorded as TDs. You can display your location as a TD 

or enter waypoints as TDs. The accuracy to be expected from this 

conversion is approximately 30 meters. When the unit is placed 

in the LORAN TD format mode, it simulates the operation of a 

LORAN receiver. Position coordinates might be shown as TDs, 

and all navigation functions may be used as if the unit was actually 

receiving LORAN signals.

When creating new waypoints using LORAN TD coordinates, 

you must set the correct LORAN chain number and secondary 

stations in the Setup TD field before storing the waypoint. After 

the waypoint is stored in units memory, it will always reference the 

LORAN chain number and secondary stations currently selected in 

the Setup TD field. If you enter a different LORAN chain number 

or change the secondary stations or offsets in the Setup TD field, 

the active waypoint information will reflect those changes. Because 

the GPSMAP 378/478 does not rely on the LORAN signal for 

navigation, it can reference a different GRI chain and/or secondary 

stations and still navigate to the location stored in memory.
The LORAN Location Format field is located on the Location sub 

tab on the Main Menu. The LORAN TD Setup window contains 

the fields to select the Loran GRI-Chain Number, Primary and 

Secondary Stations, and TD Offsets.

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LORAN TD S

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