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Target Filters
There are several filters which allow you to control which targets are included in the target
list and may be displayed. These give you the ability to limit the target list and are most
useful when operating in areas with large amounts of vessels. Any filter can be turned off. If
all filters are turned off, then all possible targets are included in the target list and all targets
may trigger alarms.
When a target is filtered, it is not shown in the target list. No alarms are triggered for
filtered targets.
Target range filter Specifies the maximum range (distance in nautical miles) for targets. Any
targets farther away than this distance will not be included in the target
list and will not trigger alarms.
This allows you to only view and trigger alarms for targets that are
“nearby” and filters out targets that are farther away.
It is not recommended to set this value too low since it may filter out
all targets and alarms.
Target speed filter Specifies the minimum speed (in knots) a target must be moving. Any
targets moving slower than this speed will not be included in the target list
and will not trigger any alarms.
This allows you to eliminate from the target list and prevent alarms for
targets which are stationary or moving very slowly. It is most useful when
there are large numbers of anchored or moored vessels in your operating
area.
It is not recommended to set this value too high since it may filter
out all targets and alarms.
Target CPA filter
Specifies the maximum CPA allowed for a target to be visible. All targets
with a CPA greater than this value will be filtered and not shown. You can
also select “Non-Converging” which causes all targets which are not
converging (they have no CPA) to be filtered.
This allows you to eliminate from the target list all targets which are either
moving away from you or will pass at a safe distance. It is most useful
when there are many moving targets.
Target TCPA filter Specifies the maximum TCPA allowed for a target to be visible. All
targets with a TCPA greater than this value will be filtered and not shown.
This allows you to eliminate from the target list all targets which are not
going to be nearby soon. It is most useful when there are many moving
targets.
Target Alarms
There are two types of target alarms provided by the
AIS
WatchMate.
They are called Guard
Alarm and CPA Alarm. Each alarm applies independently to each target. This means that