Gps - Elevation Mask Control - Leica MX420 Operator's Manual

Configuration
GPS - Elevation Mask Control
Operator's Manual
This screen controls the elevation mask angle, or the angle above the
horizon, at which the receiver will attempt to track a satellite. Satellites
with an elevation below this angle will be tracked but will not be in-
cluded in the position solution. You can set the elevation limit to any
value up to 45°. For most marine applications, the default limit of 5° is
appropriate. However, there may be some applications where the re-
ceiver is used where a higher elevation limit is desired. For example, if
you are trying to get the best possible position from the receiver and
the environment you are in has significant foliage which causes low
elevation satellites to "pop in and out," you might choose to set the
elevation limit to 15° so that only satellites above the tree line are
tracked.
The Antenna OjJset allows you to virtually offset your antenna. That
is, if you are forced to place the antennain a location other than
where you want your position fix calculated (due to superstructure
or other high power antennas), you can place the antenna in a
practical location. Then enter the appropriate Antenna OjJset, and
the receiver will calculate your position in the place where you
would have preferred to place the antenna. For example, if the
antenna is placed on the port wing of a container ship, and you want
to calculate the ship's position based on the keel line and half the
length of the ship, you might enter an offset of 10 meters Starboard
and 53 meters Forward.
It
is
important to note that many applications where an antenna
ojJset
is
desirable, will also require very precise positioning at
slow speeds to locate crab pots, place buoys, etc. In applications
where the boat speed
is
very slow, the course over ground (COG)
position will begin jumping more and more as you approach a full
stop. This will cause position jumps and these jumps will be more
severe the farther the antenna ojJset projection is. Should you
choose to use this feature, it
is
required that you use a compass
input to the receiver, so that the proper orientation between the
antenna, the antenna offset, and the boat 's heading can be main-
tained.
nit Pas - Initial Position
Entry
This screen is provided to help the GPS receiver in the MX42 I antenna
to get a faster first position fix. While the MX42 I is capable ofcomput-
'ersion
7.5
707