NorthStar Navigation 941X GPS Receiver User Manual


 
Rev. D 8 — Customizing the 941X
8 — Customizing the 941X8 — Customizing the 941X
8 — Customizing the 941X Page 83
GPS
can be selected as the navigation source at any time.
EXTERNAL LORAN
can be used if a loran receiver is interfaced
to the 941X (and is operational).
PHANTOM LORAN
can be used if no loran receiver is inter-
faced to the system, but you’d like to see your position displayed
in TD coordinates.
DEMO
mode is used to simulate a stationary position—namely,
the unit’s last position fix—if you want to practice using the 941X
without being on your boat or connected to an antenna. You may
enter a waypoint with the name “DEMO” to establish a new
demo position at that waypoint’s coordinates.
(NAVIGATION OPTIONS)
(NAVIGATION OPTIONS)(NAVIGATION OPTIONS)
(NAVIGATION OPTIONS)
Compasses naturally point to the
magnetic
north pole, which is several
hundred miles from the Earth’s actual north pole. The difference be-
tween the two angles is known as
magnetic variation
. The 941X offers
you the option of choosing from True
TrueTrue
True (0°), Automatic
AutomaticAutomatic
Automatic (the 941X calcu-
lates variation automatically, according to your location), and Manual
ManualManual
Manual
(from 0° to 180°, East or West) settings. The factory default is magnetic,
to coincide with your compass. Your navigation charts will indicate the
approximate magnetic variation for each area.
Under most conditions, you’ll want the 941X to calculate the variation
automatically
for your position. (Usually, the automatically-calculated
variation is entirely adequate for use.)
True
bearings are usually required when using a gyrocompass.
The
manual
setting (1° to 180°) is available for those times when the dis-
play must match an older or less accurate chart, or in remote areas (usu-
ally above 70° latitude) where magnetic calculations can be off by as
much as a degree or more.
NOTE
If your 941X is equipped with an internal beacon receiver, dif-
ferential GPS corrections (if available) will always be used
when “GPS” or “Phantom Loran” is selected as the navigation
source.
magnetic
variation