Garmin GPSMAP 378 Owner's Manual

Contents

Garmin GPSMAP 378 Owner's Manual Manual pdf 132 page image

LORAN TD SetupLORAN C is a radio navigation aid operated and maintained in theUnited States by the United States Coast Guard. LORAN(LOng RAnge Navigation) system covers the entire United Statesand the U.S. Coastal Confluence Zone. From the perspective of amariner, the system is used for ocean and coastal navigation. It canbe used as a supplemental system for harbor and harbor approachnavigation, and it is used for inland navigation by recreationalvehicles.LORAN TD FeatureThe LORAN TD (Time Delay) feature eases the transition fromusing LORAN to using GPS. The GPSMAP unit automaticallyconverts GPS coordinates to LORAN TDs for those who have acollection of LORAN fixes for favorite fishing spots and otherwaypoints recorded as TDs. You can show your location as a TDor enter waypoints as TDs. The accuracy to be expected from thisconversion is approximately 30 meters. When the unit is placedin the LORAN TD format mode, it simulates the operation of aLORAN receiver. Position coordinates might be shown as TDs,and all navigation functions can be used as if the unit was actuallyreceiving LORAN signals.Using the LORAN TD FormatWhen creating new waypoints using LORAN TD coordinates, youmust set the correct LORAN chain number and secondary stations inthe Setup TD field before storing the waypoint. After the waypointis stored in the unit’s memory, it will always reference the LORANchain number and secondary stations currently selected in theSetup TD field. If you enter a different LORAN chain number orchange the secondary stations or offsets in the Setup TD field, theactive waypoint information will reflect those changes. Becausethe GPSMAP 378/478 does not rely on the LORAN signal fornavigation, it can reference a different GRI chain and/or secondarystations and still navigate to the location stored in memory.The LORAN Location Format field is located on the Location subtab of the Setup tab on the Main Menu. The LORAN TD Setupwindow contains the fields to select the Loran GRI-Chain Number,Primary and Secondary Stations, and TD Offsets.124 GPSMAP 378/478 Owner’s ManualAPPendIX > lorAn td setuP