3. TARGET TRACKING (TT)
3-10
3.8 TT
Symbols
and
Attributes
3.8.1 TT
symbols
The symbols used in this equipment comply with IEC 62288.
Item Symbol Status
Remarks
Initial stage
Broken circle around an echo to indicate
the target under acquisition and initial
stage of tracking, before steady-state
tracking.
Within one minute after acquisition (vector
still unreliable).
Steady tracking
Solid circle with vector indicating steady
state tracking (within three minutes after
acquisition).
(flashing)
CPA alarm
Plotting symbol (red) flashes to indicate
the target is predicted to come into CPA or
TCPA.
CPA alarm
acknowledge
Shown in red, and flashing stops after
CPA/TCPA alarm is acknowledged.
Automatically
acquired targets
(flashing)
Lost target
A red X is crossed through the TT symbol
to indicate that it is a lost target. Flashing
stops after lost target alarm is acknow-
ledged.
Initial stage
Plotting symbol selected for a target
acquired manually is shown in bold broken
lines.
Within one minute after acquisition.
Steady tracking
Manual plotting symbol in a bold solid
circle (within three minutes after
acquisition).
(flashing)
CPA alarm
(collision course)
Plotting symbol (red) flashes to indicate
the target is predicted to come into CPA or
TCPA.
Flashing stops after CPA/TCPA alarm is
acknowledged.
Manually
acquired targets
(the width of the
line for "steady
tracking" TT is
thicker than that
of the auto-
matically
acquired target)
(flashing)
Lost target
A red X is superimposed on the TT symbol
to indicate a lost target. Flashing stops
after lost target alarm is acknowledged.
Acquisition zone
(flashing)
On target passing
through operator-set
acquisition zone
Symbol is red and flashing.
Target selected
for data readout
On selected target Target data (range, bearing, course,
speed, CPA, TCPA, BCR, BCT, etc.).
Reference target
R
After three
minutes,
changes to
○
R
On reference target Used to calculate own ship’s
over-the-ground speed (echo-referenced
speed) for ground stabilization.
