Introduction
The
AIS
WatchMate
is a low power consumption device which
provides information to assist in avoiding collisions at sea. Because it
consumes very low power it may be left turned on whenever your
vessel is underway. It works by interpreting Universal Shipborne
Automated Identification Systems (AIS) messages which are sent by
a transponder installed on other vessels. AIS transponders are
mandatory on most classes of commercial shipping. The AIS system
uses two dedicated VHF channels designated for this purpose and
with the installation of an AIS receiver to pick up these signals and
the
AIS
WatchMate
you can view this information. In addition, you
can configure the
AIS
WatchMate
to generate alarms whenever the
potential for a collision may exist.
The AIS system provides several types of messages from other
vessels and stations. Each type of message is sent at a different
interval based on the navigation status of the vessel. Vessels moving
or turning faster send out navigation information more frequently
than vessels at anchor. Data received from other vessels is split
between two types: navigation information and voyage information.
Vessel navigation and position information is generated by an on-
board GPS or similar navigation device and is sent frequently.
Voyage information contains the ship's name, its destination, size,
type, cargo, etc. This data is typically only sent once every few
minutes.
The
AIS
WatchMate
provides a means to view how recently
information has been received from each vessel and this data is
designed to help you determine how accurate and dependable the
information may be at any given time.
The
AIS
WatchMate
refers to each vessel other than your own as a
target
. Associated with each target are the most recently received
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