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Loran td system – Garmin GPSMAP 182C User Manual

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GPSMAP 182/182C Owner’s Manual

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PPENDIX

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L

ORAN

TD S

YSTEM

LORAN TD System

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

United States by the United States Coast Guard. The name LORAN

is an acronym for “LOng RAnge Navigation.” The LORAN 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.

Change to Loran TD from the Units

tab on the Main Menu.

LORAN TD Feature

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 position 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 can be displayed as TDs,

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

receiving LORAN signals.

Using the LORAN TD Format

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 unit memory, it always references 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 reflects those changes. Because

the GPSMAP 182/182C 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.