Garmin GPSMAP 182 Owner's Manual

Also see for GPSMAP 182C: Owner's manual Declaration of conformity Declaration of conformity Specifications

Garmin GPSMAP 182 Owner's Manual Manual pdf 78 page image

68Appendix ALoran TDLoran TD SystemLORAN C is a radio navigation aid operated and maintained in the United States by the UnitedStates Coast Guard. The name LORAN is an acronym for “LOng RAnge Navigation”. The LORANsystem covers the entire United States and the U.S. Coastal Confluence Zone. From the perspectiveof a mariner, the system is used for ocean and coastal navigation. It can be used as a supplementalsystem for harbor and harbor approach navigation, and it is used for inland navigation by recreationalvehicles.LORAN TD FeatureThe LORAN TD (Time Delay) feature eases the transition from using LORAN to using GPS. TheGPSMAP unit automatically converts GPS coordinates to LORAN TDs for those who have a collectionof LORAN fixes for favorite fishing spots and other waypoints recorded as TDs. You can display yourposition as a TD or enter waypoints as TDs. The accuracy to be expected from this conversion isapproximately thirty meters. When the unit is placed in the LORAN TD format mode, it simulatesthe operation of a LORAN receiver. Position coordinates may be displayed as TDs, and all navigationfunctions may be used as if the unit was actually receiving LORAN signals.Using the LORAN TD FormatWhen creating new waypoints using LORAN TD coordinates, you must set the correct LORANchain number and secondary stations in the Setup TD field before storing the waypoint. You must havethe correct chain number as well as the secondary station identifiers to use this option correctly. Thesevalues will vary per coordinate set or geographical location. Failure to enter correct information couldresult in inaccuracies for the desired destionation. After the waypoint is stored in unit memory, it willalways reference the LORAN chain number and secondary stations currently selected in the Setup TDfield. If you enter a different LORAN chain number, change the secondary stations or offsets in theSetup TD field, the active waypoint information will reflect those changes. Since the GPSMAP unit doesnot rely on the LORAN signal for navigation, it can reference a different GRI chain and/or secondarystations and still navigate to the location stored in memory.You may change to Loran TD from the UnitsTab on the Main Menu.