Target Vectors And History; Acquiring Marpa Targets - Raymarine H6 Owner's Manual

81238_1.book Page 67 Thursday, September 16, 2004 2:49 PM
Using the radar

Target vectors and history

You can display MARPA targets with a vector line showing where they will be at a
certain time in the future (assuming their present course and speed remains
unchanged). You can select a relative or true vector, and the vector length.
Relative vector
A relative vector indicates the target's motion relative to your own boat's motion.
The target's relative course and speed are calculated to produce a vector that is
displayed on the target only. Relative vector mode is used for collision avoidance
and threat assessment.
True vector
A true vector indicates the target's motion over ground. In this mode, true vectors
for the target and your own boat are displayed. MARPA measures the direction in
which the target and your own boat are moving over the ground. The result is the
boat's true course and speed. Consider this motion as if you were in a helicopter
looking down watching the targets move across the water. This mode is used as
an aid to navigation.
Target history
You can also view a target's history, which appears as a trail of dots left by the
target as it travels. You can change the display interval of these dots.
Setting up target vectors and history
To set up target vectors and history:
1. Select Tools/Layers/Marpa. The vector dialog box is displayed.
2. Click the action boxes to set mode and distance as required.
3. Use the

Acquiring MARPA targets

You can acquire up to ten targets, which are then automatically tracked by the
MARPA system. The are two ways in which a MARPA target can be acquired. In
the illustration below, targets 1, 2, 3 and 4 are acquired and displayed as 'safe'.
targets 5 and 6 are being acquired.
OK
button to return to the top level softkeys.
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