Koden MDC-7010, Operation Manual

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MDC-7000/7900 Series Chapter 4 Target (AIS,TT and Trial manoeuvre)
0093169010-10 4-17
4.3 TT (ARPA)
It is an effective mean for collision avoidance by generating vectors on tracked targets.
It is an effective means for collision avoidance to set up CPA/TCPA.
If AIS information is available with tracked targets, association increases tracking accuracy.
Limitations of the TT function
There are the following limitations on use of the target acquisition and tracked target of TT (ARPA)
functions.
Note:
• If multiple targets approach each other, this may cause the system to regard them as one target and
thus to swap them or loss part of them. Such swapping or less of targets may also occur if the picture
of the target being tracked is affected by rain/snow clutter returns or sea clutter returns or moves very
close to land.
• Intensity of echoes and the TT function have a correlation ship, and thus the target will be lost if no
echoes and detected during six scans in succession. If a lost target exists, therefore, radar gain must
be increased to support detection of the target. If radar gain is increased too significantly, sea clutter
returns or other noise may be erroneously detected and tracked as a target, and resultingly, a false
alarm may be issued.
• To execute accurate tracking, it becomes necessary first to appropriately adjust the GAIN, SEA and
RAIN knobs of the radar so that the target to be acquired and tracked id clearly displayed on the radar
display. Inappropriate settings of these adjustments reduce the reliability / accuracy of automatic
tracking.