Garmin GPS 152 GPS Receiver User Manual


 
59
Reference
Main Menu:
Units Tab
Heading lets you select the reference used in calculating heading information. You can select
from Auto Mag Var, True, Grid and User Mag Var. Auto Mag Var provides magnetic north heading
references which are automatically determined from your current position. True provides headings
based upon a true north reference. Grid provides headings based on a grid north reference (and
is used in conjunction with the grid position formats described on page 58). User Mag Var allows
you to specify the magnetic variation at your current position and provides magnetic north heading
references based upon the variation you enter.
To enter a user de ned magnetic variation:
1. With the Heading eld set to User Mag Var, highlight the heading reference eld (immediately
to the right) and press ENTER/MARK.
2. Use the ARROW KEYPAD to enter the magnetic variation at your current position and press
ENTER/MARK.
WARNING: If User Mag Var is selected, you must periodically update the magnetic
variation as your position changes. Using this setting, the unit will not automatically
calculate and update the magnetic variation at your present position. Failure to update
this setting may result in substantial differences between the information displayed on
your unit and external references, such as a magnetic compass.
Distance, Speed and Altitude lets you select the desired units of measure for distance, speed and
altitude readouts in Nautical (nm, kt, ft), Statute (mi, mh, ft) or Metric (km, kh, mt) terms.
Depth* lets you select the desired units of measure for depth in Feet (ft), Fathoms (fa) or
Meters (mt).
Temperature* lets you select the desired units of measure for temperature in Fahrenheit (°F)
or Celsius (°C).
* You must be receiving proper sonar NMEA data from another device for this data to display. See pages 83-84.
,
You may manually enter a magnetic variation.
152 Manual Part 2.indd 59 11/27/2002, 2:56:35 PM