Filter
Top Products
4. Tracked Target (TT) Operation
4-18
4.13 Dangerous Target (CPA, TCPA)
The TT continuously monitors the predicted range at the Closest
Point of Approach (CPA) and predicted time to CPA (TCPA) of
each TT. When the predicted CPA of any TT becomes smaller
than a preset CPA range and its predicted TCPA less than a
preset TCPA limit, the audio alarm sounds and "TT dangerous
target" appears (in red) in the Alert Box. In addition, the symbol
of the offending TT is red and flashes together with its vector.
This feature, when used correctly, helps prevent the risk of
collision by alerting you to threatening targets. It is important
that GAIN, A/C SEA, A/C RAIN and other radar controls are
properly adjusted.
CPA and TCPA settings must be set up properly taking into
consideration the size, tonnage, speed, turning performance and
other characteristics of own ship.
4.13.1 How to set CPA and TCPA ranges
To set the CPA and TCPA ranges, do the following:
1. Use the trackball to select "CPA" of "CPA Off" at the lower right corner. Push the left button to show the CPA
and TCPA boxes.
SINGLE
SINGLE
AUTO
MAN
AUTO
MAN
xx.xx xx.xx xx.xx xx.xx
CPA and TCPA settings
2. Spin the scrollwheel to select the CPA setting desired (0.1-20 NM) then push the scrollwheel.
3. Use the trackball to select the TCPA setting.
4. Spin the scrollwheel to select TCPA value desired (1-60 min) then push the scrollwheel.
How to acknowledge the TT dangerous target alarm
The TT dangerous target alarm sounds when the CPA or TCPA of an target is within the set CPA/TCPA. To
acknowledge and silence the alarm, push the ALARM ACK key on the keyboard, or select the ALARM ACK box
with the trackball then push the left button.
The warning label "TT dangerous target" and the flashing of the plotting symbol and vector remain in the Alert Box
until the dangerous situation is gone or you intentionally terminate tracking of the target.
CPA/TCPA Alarm
The CPA and TCPA alarm feature should
never be relied upon as the sole means
for detecting risk of collision. The
navigator is not relieved of the respon-
sibility to keep visual lookout for
avoiding collisions, whether or not the
radar or other navigation aid is in use.
CAUTION