Reference Manual Part 2

G-Series Reference Manual 154
2. Toggle to the required CPA setting using the CPA GRAPHIC
softkey.
How motion modes affect CPA
In true motion mode, the vectors of your vessel and the target are
shown extended to their intersection point. The CPA is shown as a
line that is placed on your boat’s vector at the point of the CPA. The
length and direction of the line indicates the distance and bearing of
the target at CPA. The text indicates CPA and TCPA. The text next
to the target symbol indicates its true course and speed.
In relative motion mode, no vector extension of your boat is
shown. The CPA line emerges from your own boat, with the target
vector extension being shown as relative, not true. The text next to
the target indicates its course and speed.
Press SHOW DETAILS to display the calculated relative course
and speed.
Displaying MARPA data
All MARPA data is held in a list containing:
• MARPA ID
• Bearing
• Range
• True Course
• True Speed
• CPA
• TCPA
Target display
The position of MARPA objects is marked with an icon, which also
indicates its MARPA status.
To view the MARPA list
1. Press the TARGET TRACKING softkey.
2. Press the MARPA LIST softkey.
To cancel MARPA directly
1. Highlight a tracked MARPA object.
2. Press either the CANCEL TARGET or CANCEL ALL
TARGETS softkey, as appropriate.
To cancel MARPA from the MARPA list
1. Open the MARPA list.
2. Select a target and press CANCEL TARGET or CANCEL ALL
TARGETS, as required.
Displaying vessel identity (AIS)
If you have an AIS receiver fitted to your system, you can use it to:
• Show the position and display vessel data for other AIS-
equipped vessels within a specified range of your boat.
• Display voyage data (position, course, speed and rate of turn)
of AIS-equipped vessels.
• Display basic or detailed information for each target vessel in-
cluding safety critical target data.
• Set up a safe zone around your boat.
• View alarm and safety related messages.
This information is displayed in the form of an overlay or as a dialog
box on your radar screen. For more information about AIS, see
Chapter 12:Automatic Identification System on page 157.
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Dangerous target
Safe target
Target being acquired
Lost target