Garmin 168 sounder Manuale Proprietario

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74
Reference
Main Menu:
Units Tab
The Units tab settings will affect how navigation information 
is displayed on the GPSMAP 168 Sounder. When in doubt, 
seek assistance.
If you are using a map or chart in conjunction with your 
GPS, make sure the settings under the ‘Units’ tab of the 
GPSMAP 168 Sounder match that of the map or chart. This 
information should be displayed somewhere on the map or 
chart. If the information is not present, contact the map 
or chart maker to determine what position format, datum, 
heading and units of measure are being used for the map 
or chart.
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Units Tab
Units Tab— defi nes the settings for Position Format, Map Datum, Heading, and the units of measure 
for Distance, Speed, Elevation, Depth and Temperature. 
The following settings are available:
•    Position Format— is used to change the coordinate system in which a given position reading is 
displayed. You should only change the position format if you are using a map or chart that specifi es a 
different position format or wish to use a format you are familiar with. The default format is latitude 
and longitude in degrees, minutes, and thousandths of a minute (hddd°mm.mmm’). The following 
additional formats are available:
 
• hddd.ddddd°— latitude/longitude in decimal degrees only
 
• hddd°mm’ss.s”— latitude/longitude in degrees, minutes, seconds
 
• UTM/UPS— Universal Transverse Mercator / Universal Polar Stereographic grids
 
• British Grid 
• Dutch Grid  
• Finnish KKJ27 
• German Grid 
 
• Irish Grid 
• Maidenhead 
• MGRS   
• New Zealand 
 
• Qatar Grid 
• RT 90   
• Swedish Grid 
• Swiss Grid
 
• Taiwan Grid  
• Loran TD  
• User Grid 
• W Malayan RSO
For additional information on Loran TD setup, see pages 83-84.
•    Map Datum— allows you to select the datum reference used to determine a given position. The 
default setting is ‘WGS 84’. Datums are used to describe geographic positions for surveying, 
mapping, and navigation and are not actual maps built in the unit. Although over 100 datums are 
available (as listed on pages 88-89), you should only change the datum if you are using a map or 
chart that specifi es a different datum. 
WARNING: Selecting the wrong map datum can result in substantial position errors. 
When in doubt, use the default WGS 84 datum for best overall performance.
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168 Manual Part 2.indd   74
11/18/2002, 3:37:59 PM