Garmin GPSMAP 188 Owner's Manual And Reference Manual

Also see for GPSMAP 188 Sounder: Declaration of conformity Declaration of conformity Owner's manual Specifications

Contents

Garmin GPSMAP 188 Owner's Manual And Reference Manual Manual pdf 112 page image

On the Units Tab ofthe Main Menu, pressMENU, then highlight‘Loran TD On’ andpress ENTER to selectLoran TD.Or, highlight the PositionFormat field, highlight‘Loran TD’ and pressENTER to select Loran TD.102Appendix DLoran 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 perspective ofa mariner, the system is used for ocean and coastal navigation. It can be used as a supplemental systemfor harbor and harbor approach navigation, and it is used for inland navigation by recreational vehicles.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 collec-tion of LORAN fixes for favorite fishing spots and other waypoints recorded as TDs. You can displayyour position 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 simulates theoperation of a LORAN receiver. Position coordinates may be displayed as TDs, and all navigation func-tions 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 musthave the correct chain number as well as the secondary station identifiers to use this option correctly.These values will vary per coordinate set or geographical location. Failure to enter correct informationcould result in inaccuracies for the desired destination. After the waypoint is stored in unit memory, itwill always reference the LORAN chain number and secondary stations currently selected in the SetupTD field. 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.