Collision Alarm (Cpa, Tcpa); How To Set The Cpa And Tcpa Ranges; How To Acknowledge The Tt Collision Alarm - Furuno FAR-1513-BB Operator's Manual

3. TARGET TRACKING (TT)
3.14

Collision Alarm (CPA, TCPA)

This radar calculates CPA and TCPA by using own ship and relative target positions.
The TT continuously monitors the pre-
dicted range at the Closest Point of Ap-
proach (CPA) and predicted time to
CPA (TCPA) of each TT. When the pre-
dicted CPA of any TT becomes smaller
than a preset CPA range and its predict-
ed TCPA less than a preset TCPA limit,
the audio alarm sounds and TT COLLI-
SION 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 con-
trols are properly adjusted.
CPA and TCPA ranges must be set up properly taking into consideration the size, ton-
nage, speed, turning performance and other characteristics of own ship.
The reference point for CPA and TCPA calculation can be selected from antenna po-
sition or conning position. For further details, see section 1.48.
3.14.1

How to set the CPA and TCPA ranges

CPA and TCPA ranges can be ad-
justed from the appropriate indica-
tion in the [TT] box.
1. Place the cursor on the indication you wish to adjust.
2. Press the left button, or rotate the ADJUST knob, to adjust the settings as re-
quired. The settings options are outlined in the table below.
Indication
CPA
TCPA
3.14.2

How to acknowledge the TT collision alarm

Press the ALERT ACK key on the control unit, or select the [ALERT] box with the
Touchpad then press the left button to acknowledge the alarm and silence the buzz-
er. The alert "TT COLLISION" and the flashing of the plotting symbol and vector re-
main in the Alert Box until the dangerous situation is gone or you intentionally
terminate tracking of the target.
Note that when the TT COLLISION alarm is generated the AIS display is automatically
turned on.
3-14
Key
Left button 0.5, 1, 1.5, 2, 3, 4, 5, 6 (nm)
ADJUST knob 0.1-20 (nm), 0-10 nm in 0.1 nm increments, 10 nm in-
crements thereafter
Left button 1, 2, 3, 4, 5, 6, 12, 15 (minutes)
ADJUST knob 1-60 minutes, 1-minute increments
CAUTION
CPA/TCPA Alarm
The CPA and TCPA alarm feature should
never be relied upon as the sole means for
detecting the risk of collision.The navigator
is not relieved of the responsibility to keep
visual lookout for avoiding collisions,
whether or not the radar or other plotting
aid is in use.
CPA setting
TCPA setting
Settings options