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Target Display
The target display screen is shown when you select a target from the target list or situation
display. This screen contains detailed information about the target. The information
displayed will vary depending on how much data has been received from the target and the
type of target.
AIS data for a target is received in several types of messages and those messages may be
received at different times. The interval at which a target sends messages is based on the
type of message, class of target, its speed, rate of turn and other factors. As a result certain
information may not be available immediately from a target. However, the
AIS
WatchMate
displays available information as soon as it has been received. If you are viewing a target
when new data arrives for that target, the screen is refreshed with the new data.
Until voyage information has been received for a target, its name is not available. In this
case its MMSI number will be displayed instead of the name and will look like
<735023456>
. Since voyage information is received at a different interval than navigation
information it may take several minutes to appear.
A target may specify its navigation status and if available it is displayed as “Motoring”,
“Sailing”, “Anchored”, “Moored”, etc.
The navigation status may not be accurate.
An important piece of information indicates when data was last received from a target. This
is shown at the bottom of the target details screen. Although bearing, range, CPA, and
TCPA are constantly updated by the
AIS
WatchMate
as your vessel moves, you should
consider the “age” of the information received from the target in determining how accurate
the displayed data may be and to assist you in refining your assessment of collision risk.
If the target and your vessel will not converge, such as when they are moving away from
each other, the CPA is shown as
None
and TCPA is not displayed.
When the TCPA is greater than one hour it is displayed in minutes without the seconds (eg.
123
min
).
When the target display screen is shown due to an alarm condition the reason for the alarm
will be blinking (eg.
RNG
for a guard alarm and
CPA
for a CPA alarm). The blinking stops
when the alarm is muted or the target is no longer in an alarm condition.
