Furuno FAR-2805 Series Operator's Manual page 69

ARPA symbols
The symbols used in this equipment are designed to comply with Annex E (ARPA
Video Symbols) to IEC 872, Operational Requirements for ARPA.
Item
Automatically
acquired targets
Manually
acquired targets
2-8
Symbol Status
Initial stage
EPVS symbol NO. 3
EPVS symbol NO. 3
Steady tracking
EPVS symbol NO. 4a
CPA alarm
(flashing)
EPVS symbol NO. 8
CPA alarm
acknowledge
EPVS symbol NO. 8
Lost target
EPVS symbol NO. 9
(flashing)
Initial stage
EPVS symbol NO. 3
EPVS symbol NO. 3
Steady tracking
EPVS symbol NO. 4a
CPA alarm
(collision course)
(flashing)
EPVS symbol NO. 8
EPVS symbol NO. 8
Lost target
(flashing)
EPVS symbol NO. 9
Remarks
Broken square around an echo to
indicate the target under acquisition
and initial stage of tracking, before
steady-state tracking.
Between 20 and 60 scans of antenna
after acquisition (vector still unreliable)
Solid circle with vector indicating
steady state tracking (60 scans after
acquisition)
Plot symbol changes to an equilateral
triangle flashing to indicate the target is
predicted to come into CPA or TCPA.
Flashing stops after CPA/TCPA alarm
is acknowledged.
Lost target is indicated by flashing
diamond symbol. The diamond is
formed from two equal triangles.
Plot symbol selected for a target
acquired manually is shown in bold
broken lines.
Bold broken square for 20 - 60 scans of
antenna after acquisition.
Manual plot symbol in a bold solid
circle (60 scans after acquisition)
Plot symbol changes to an equilateral
triangle flashing if a target is predicted
to come into the preset CPA or TCPA.
Flashing stops after CPA/TCPA alarm
is acknowledged.
Lost target is indicated by flashing
diamond symbol. The diamond is
formed from two equal triangles (one
apex up and the other apex down).