Appendix D: Map Datum And Location Formats; Map Datums; Location Formats - Garmin G3X Pilot's Manual

APPENDIX D: MAP DATUM AND LOCATION
FORMATS

MAP DATUMS

A datum is a mathematical model of the Earth that approximates the shape of the
Earth and enables calculations to be carried out in a consistent and accurate manner.
The datum is physically represented by a framework of ground monuments (such as
trig. stations) whose locations have been accurately measured and calculated on this
reference surface. Lines of latitude and longitude on a chart are referenced to a specific
map datum. Every chart has a map datum reference and the G3X can be set to match
most of those commonly used.

LOCATION FORMATS

Your current location can be viewed on the GPS in the form of coordinates. Since
different charts use different location formats, Garmin GPS units allow you to choose
the correct coordinate system for the type of chart you are using. The most common
format is latitude and longitude, which is used by all Garmin units. You can change the
location format to use with other coordinate systems.
Map Datum and Location Format selection can be performed on the Position Setup
Page.
Changing position settings:
1) Press the MENU Key twice to display the Main Menu.
2) Turn or move the FMS Joystick to highlight 'System Setup...' and press the
ENT Key.
3) Turn or move the FMS Joystick to highlight 'Position' and press the ENT
Key.
4) Move the FMS Joystick to highlight the desired field, and select the desired
option by turning the FMS Joystick.
5) Press the FMS Joystick, the CLR Key, the EXIT Softkey or the MENU Key to
remove the menu.
190-01115-00 Rev. K Garmin G3X Pilot's Guide
Appendix D
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