NorthStar Navigation Multi-Function Unit M84 - Manual (Page 59)

Northstar M121/M84 Installation and Operation Manual 58
16-3 AIS Windows
To go to the AIS windows, press , select
More , select AIS, then press or to select
one of the two windows: Vessels or Safety msgs
(rx).
If there are more items than will fit on the
window, press
or to see the others.
Vessels
This is a sorted list of vessels currently being
received by the AIS receiver. The maximum
number of vessels that the system will support
is 250. Once maximum is reached, vessels
furthest away from the current location will be
replaced. A vessel will be removed from the list
if no information is received within 6 minutes
from the last message.
Displaying an AIS vessel on the chart
1 Press or to select a vessel.
2 Press and select Display. The
Instrument switches to chart window, with
the selected vessel position in the middle.
16-2 Dangerous Vessels
The M121/M84 calculates the time of closest
point of approach (TCPA) and closest point of
approach (CPA) for each AIS vessel.
This is used to determine potential dangerous
vessels. If the TCPA and the CPA is below
the trigger values then it will be considered
dangerous. (See section 19-8 for setting the
dangerous vessel alarm)
A dangerous vessel is indicated on the chart by
a red circle around the icon.
When the cursor is placed over an AIS vessel for
at least two seconds, a data box appears at the
bottom of the window with information about
the AIS vessel.
For complete AIS information on the AIS vessel
place the cursor over an AIS vessel for at least
two seconds and press
.
Press either or to clear the
information.
TCPA 15 min
CPA 0.5 nm