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7 ais, 1 ais system definitions – Seiwa SW701i SW701e User Manual

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User Manual

with the value given by the compass of the boat. In other words, since the compass of the boat
must be compensated (due to the iron masses, ...), we use the same values given by the chart
plotter. This means that, for example, if the BRG to the next Waypoint readout in the chart
plotter display is "X" Mag degree, if you steer the boat reading "X" Mag degree from the
compass, you are driving well toward the next Waypoint.

NOTE

1

A

VAILABLE

F

OR

SW1101/SEAWAVE

3

/MARLIN/EXPLORER

3

.

3.7

AIS

AIS is an Automatic Identification System. It has been introduced to improve the

safety of navigation by assisting in the efficient operation of ship-to ship, ship

reporting and VTS applications. The system should enable operators to obtain

information from the ship automatically, requiring a minimum of involvement of

ship’s personnel, and should have a high level of availability. AIS transponders

installed on IMO vessels use VHF frequencies to:

Transmit details of their own vessel

Receive details from other vessels or navigation aids within VHF range.

Information being transmitted from vessels over 300 tons that, due to recent

worldwide legislation, are required to fit Class “A” AIS transponders.

Connecting to the chart plotter an AIS receiver (please contact your local dealer),

vessels with AIS transponder within VHF range are displayed on screen giving the

skipper or navigator a visual interpretation of the data of nearby vessels. This

improves safety, and specifically for collision avoidance reasons.

3.7.1 AIS System Definitions

Target

It is a vessel equipped with AIS. Information about the Targets is being

received by AIS Receiver and displayed on the screen.

CPA

Closest Point of Approach is the closest distance that will be achieved be-

tween your vessel and the tracked Target, based on your vessel’s speed

and direction and the Target’s speed and direction.

CPA Limit

This is the distance from your vessel that a Target may reach before a

Target is deemed a threat.

CPA Alarm

Occurs if CPA is less or equal to CPA Limit. This test is done for active

Targets only.

TCPA

Time to closest Point of Approach is the time remaining until the CPA will

occur.

TCPA Limit

This is the time remaining before the CPA is reached.

TCPA Alarm

Occurs if TCPA is less or equal to TCPA Limit. This test is done for active

Targets only and if CPA value is less or equal to CPA Limit.

Radio Call Sign

International call sign assigned to vessel, often used on voice radio.

Name

Name of ship, 20 characters.

MMSI

Maritime Mobile Service Identity.

MMSI number

A unique 9 digit number that is assigned to a DSC radio station. It prima-