5-47 
 
z  If the gain, sea clutter suppression, rain/snow clutter 
suppression are not adjusted adequately, the lost 
target alarm may be easily generated.  So such 
adjustments should be mad carefully. 
Lost Target Alarm 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
When it is impossible to continue tracking any acquired and tracked target, or the data of AIS target cannot 
received for a specified time, the    LOST    alarm will be generated.    The typical causes for alarm 
generation are shown below, but not limited to the following: 
•  The target echo is very weak. 
•  The target is shadowed by a shore or a large ship and its echo is not received. 
•  The target echo is blurred by sea clutter returns. 
If a target under tracking goes out of a range of 32 nm and can no longer be tracked, it is canceled without a 
lost target alarm. 
 
 
Lost Target Alarm 
 
Status  Symbol on display  Alarm characters  Alarm sound  Conditions 
Lost target 
 
 
 
 
 
 
 
 
 
 
 
Red Blinking 
Lost 
Beep sound (pee) 
Alarm 
acknowledgeable
 
The alarm will sound once 
when a lost target symbol is 
displayed. 
 
 
Gyro Set Alarm 
 
The GYRO I/F in this system receives signals from a gyro.    Even if the power is turned off, the system will 
follow up the gyro.    However, the system stops the follow-up operation when the power of the master gyro 
is turned off or when any trouble occurs to the line.    When the power of the master gyro is recovered, the   
  Set Gyro    alarm will be generated. 
If this alarm occurs, set the gyro. 
 
Gyro Set Alarm 
 
Alarm characters
  Alarm sound 
Conditions 
Set Gyro  Beep sound (pipi-pipi)
The signals from the gyro are stopped, but the gyro is 
recovered. 
Attention
12 
AIS12