Map Datums - Garmin GPS 155XL Pilot's Manual & Reference

SECTION
UNIT SETTINGS
6

Map Datums

Map datum page showing the default WGS 84
datum. This setting should be used unless your
paper chart specifies a different datum.
User datum page. To use this function you must
enter the parameters as differences from the WGS
84 default.
106
The NavData card contains over 100 map datums for you to use when navigating.
By default, your unit calculates positions using the WGS 84 map datum. If you are
using charts based on another datum, you must set the GPS 155XL to use the same
datum. Using a map datum that does not match the charts you are using can result in
significant differences in position information. If you are using maps for reference
only, the GPS 155XL will provide correct navigation guidance to the waypoints
contained in the database, regardless of the datum selected.
To change the map datum to one listed in Appendix F:
M
1. Press and hold , and use
C
2. Press to highlight the current map datum.
K
3. Use to change the datum.
C
4. Press to complete.
To create a user datum:
M
1. Press and hold , and use
C
2. Press .
O
3. Use to highlight 'Define user datum?'. Press
4. Enter the five parameters of the map datum using
field. The signs of each value (+/-) should follow the convention: WGS84-local geodetic
system.
O
5. Use to highlight 'ok?', and press
6. To activate the user datum, select 'USER' on the map datum page as described above.
O
to display the map datum page.
O
to display the map datum page.
E
.
K O E
and . Press
E
.
to accept a