5─25
5.2.6 Alarm Display
The ATA system provides the following alarms:
Dangerous target alarm: CPA/TCPA
Guard zone entry alarm: GZ
Lost target alarm: LOST
System function alarm: ATA (DATA)
Gyro set alarm: SET GYRO
Dangerous Target Alarm
CAUTION
Since these alarms may include some errors
depending on the target tracking conditions, the
navigation officer himself should make the final
decision for ship operations such as collision
avoidance.
Making the final navigation decision based only on
the alarm may cause accidents such as collisions.
In the ATA system, targets are categorized into two types: tracked targets and dangerous targets.
The grade of danger can easily be recognized on the display at a glance. So the officer can easily decide
which target he should pay attention to.
The types of target and alarm are shown below.
Dangerous Target Alarm
Status Symbol on display Alarm characters Alarm sound Conditions
Tracking target
{
(OFF)
(OFF)
• CPA>CPA LIMIT
• 0>TCPA
• TCPA>TCPA LIMIT
Dangerous target
TCP/TCPA
Beep sound (pee-poh)
Acknowledgeable
• CPA≤
CPA LIMIT,
0≤TCPA≤TCPA LIMIT
CPA LIMIT and TCPA LIMIT: The Setting Values