User Manual
Reference number: 4111A-RADAR4600-GBD-R1.1
Date: 27 February 2018
Page 108 of 149
4.3
Trial manoeuvre
Trial manoeuvre is used to analyse the expected positions of own ship and all targets around during a
certain manoeuvre of own ship.
Starting conditions are the actual values of own ship speed and course. The shown examples are calculated
with SOG and COG.
Following parameter must be set for own ship to simulate a planned course change:
Parameter describing the intended manoeuvre:
-
a true course to follow at the end of manoeuvre
-
a trial speed during manoeuvre
Parameter describing the dynamic of the vessel
-
the maximum acceleration to reach the trial speed
-
a turn rate matching the dynamics of own ship to reach the new course
-
a delay time till start of turn.
A delay time is necessary:
a.
If the set of trial speed is higher than the actual speed, because the calculation of turn circle only is
possible, when the trial speed is reached. So the delay time must be equal or higher than the
acceleration time.
b.
If the turn circle and the new course vector has to be shifted into forward direction.
(If the set acceleration time is shorter than the needed time to reach the manoeuvre speed, the set
time value will be shown yellow coloured.)
After starting the simulation, predicted path from actual to predicted position for own ship and targets are
indicated by dotted lines. For own ship this predicted path is separated into three segments:
-
first segment for the delay time
-
second segment marking the turn circle
-
third segment as heading vector for the selected new course.
-
A big magenta “T” is shown in lower part of screen, to warn the navigator that a simulated trial manoeuvre
is activated.
ATTENTION!
If a trial manoeuvre is activated, the predicted path depends on the selected motion mode only (RM or TM).
The display of relative or true vectors is set independently from the motion mode
Note:
To show own ship prediction line, TM must be activated.
Note:
In case a trial manoeuvre is activated, real CPA/TCPA alarms shall be activated anyhow. But then
they are only shown in alarm window of right side menu and not inside of radar image.
Inside of radar image only CPA/TCPA targets will be indicated as dangerous, which are dangerous
according to the path of trial manoeuvre. In case such a target is detected as dangerous during and
also behind of trial cycle, this target symbol and the predicted path shall be shown red coloured.