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3 minutes
10 seconds
3.3 seconds
6 seconds
2 seconds
2 seconds
2 seconds
Operator's Manual
Automatic Identifaction System
Ship's draft
Hazardous cargo (type)
Destination and ETA (at master's discretion)
Safety-related messages
As needed
Dynamic information is derived from interfaces with the ship's GPS and other
sensors. Static information is programmed into the unit at commissioning. Voy-
age-related data is entered manually by the master through a password-pro-
tected routine. Safety messages can be inserted at any time by the ship or shore
station. The static and voyage-related data are transmitted every six minutes,
when amended Of-on request (for instance, when interrogated by a Vessel Traffic
System operator). Safety messages are sent as needed. The update rates for
dynamic information will depend on the ship's status and speed, according to
the following schedule:
At anchor
0-14 knots
0-14 knots and changing course
14-23 knots
14-23 knots and changing course
23+ knots
23+ knots and changing course
The AIS specifications also allow for insertion of brief binary messages from
ships or shore stations. Such messages might include notices to mariners, navi-
gational warnings, tides and currents, weather forecasts, SAR communications
and ship-specific instructions from a VTS operator. The AIS standard also in-
cludes formats for transmission ofdifferential GPS error correction data. This can
provide valuable redundancy to existing beacon DGPS systems in critical navi-
gation areas.
140
Version 1.5
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