User's Manual

ED 3038 G 232 / 01 (2002-06)
Operating Instructions
3 PPI Settings
3.6 Own Ship Symbols and Target Symbols, Vectors, Past Position Plots
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RADARPILOT / CHARTRADAR
be set. The setting of the time marker spacing also defines the length of the plot that is displayed.
This setting and the on/off switching of the past plot display take place in common with the past plots
and time markers of the radar targets.
- Stern line: This extension of the heading line in the aft direction as
far as the edge of the PPI can be switched on if necessary. (For the
setting procedure, see page 35.)
- Path Prediction: In the small display ranges up to 1.5 NM, it is
possible to display the probable track along which own ship will travel
if it maintains its existing rate of turn and its existing speed. The
prediction time can be set, see page 35.
Radar Target Symbols
Targets being tracked on the EPA radar or ARPA radar are displayed in
all display ranges as circular symbol
1)
. The following elements can be
provided for them:
- Speed vector: The direction of the vector corresponds to the existing
course of the target, and the length corresponds to the existing speed
of the target. Together with the speed vectors of the own ship
symbol, the display of the speed vector can be switched on and off.
The length of the vector is computed from the distance travelled by
the vessel in the "vector time", as it is called. The vector time can be
adjusted.
☞ In the case of the manual plotting aid (EPA radar), the vector is
computed from the last two (manual) plots. Therefore, particular
care is required when plotting on the EPA radar: if the target
being plotted changes its course or speed between two plots,
the vector displayed does not correspond to the actual vector.
- Past position plot:
In the case of the ARPA radar, past position plots can be displayed
for the targets. The settings for these plots are made jointly with
those of own ship’s past position plot. They have four time markers
at the most, which are set simultaneously on all past position plots.
In the case of the EPA radar, the last four plots are joined up by a
line. Thus, these markers - in contrast to the time markers of the
ARPA radar - are not at constant time-intervals apart from each
other, i.e. they also have no relation to each other.
All vectors and past position plots can be displayed jointly either relative
to own ship (R = relative display) or over ground or through the water (T
= true display).
☞ In the case of the relative display, the vector and the past position
plot of own ship are non-existent by definition.
Furthermore, the radar target symbols are supplemented by symbols of
the manual plotting aid or of the automatic target tracking function (see
page 67).
The computation of the vectors is always based on the BT/WT setting
which is displayed for the selected speed sensor.
1)
Other symbols, see page 67
Path Prediction
Prediction
Time
Target symbol
on the ARPA radar
Speed vector
Past position plot
with time markers
Past position plot
with manual plots
Target being
Target symbol
on the EPA radar
Speed vector
plotted
Target being
plotted