Raymarine C140w - Manual (Page 126)

the dangerous target symbol and flashes to indicate that it is a
dangerous target. Pressing the appropriate soft key will silence the
alarm and remove the warning.
If a target is lost, either because the MARPA software has lost
contact with it, or because it has moved out of range, an audible
alarm is sounded and an on-screen warning appears. The
on-screen symbol will change to the target lost symbol. Pressing the
appropriate soft key will silence the alarm and remove the on-screen
warning and the target lost symbol.
Effective range for MARPA targets
MARPA target acquisition is only available at radar range scales of
up to 12nm, although tracking continues at all ranges.
If you change to a smaller range scale, targets may be beyond the
range of your scanner and will be lost. In such cases, an on-screen
warning will indicate that the target is off-screen.
Status symbols for MARPA targets
Each target is shown in the radar display as a symbol, which
indicates its status:
D7542_2
Dangerous target
Safe target
Target being acquired
Lost target
Vessel vectors (CPA graphics) overview
CPA graphics show vectors for your vessel and a selected target.
A vector is a line on-screen showing the predicted courses of your
vessel and the selected target if you both remain on your present
course. These vectors vary in length due to vessel speed and vector
length set in the MARPA Setup menu.
D9008_1
V ector
CP A graphic
3 9
True mode
With the display set in True 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 vessel’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.
Relative mode
With the display set in Relative mode, no vector extension of your
vessel is shown. The CPA line emerges from your own vessel, with
the target vector extension being shown as relative, not true. The
text next to the target indicates its course and speed.
Setting up MARPA
In the radar application:
1. Press the TARGET TRACKING softkey.
2. Press the MARPA AND AIS OPTIONS softkey.
126 C-Series Widescreen user reference