vi
B.1
M
ONITORING OF
S
YSTEM
F
UNCTIONS AND
I
NTEGRITY
......................................................................... 93
B.2
A
NTENNA
VSWR
E
XCEEDS
L
IMIT
...................................................................................................... 93
B.3
D
ETECTION OF
T
X
M
ALFUNCTION
...................................................................................................... 93
B.4
D
ETECTION OF
R
X
M
ALFUNCTION
...................................................................................................... 93
APPENDIX (C) ................................................................................................................... 94
I
NSTALLATION AND
M
AINTENANCE
R
ECORD
.................................................................................................... 94
S
OFTWARE
R
EVISIONS
................................................................................................................................... 96
1
1 WHAT IS AIS?
The Automatic Identification System (AIS) is a Very High Frequency (VHF) radio broadcasting
system that transfers packets of data over the VHF data link (VDL) and enables AIS equipped
vessels and shore-based stations to exchange identification information and navigational data.
Ships with AIS transponders continually transmit their ID, position, course, speed and other data to
all nearby ships and shore stations. Such information can aid greatly in situational awareness and
provide a means to assist in collision avoidance.
AIS equipment is standardized by ITU, IEC, IALA and IMO and is subject to approval by a
certification body. The following AIS devices have been developed for variant applications.
AIS Class A:
mandated by the IMO for vessels of 300 gross tonnages and upwards engaged on
international voyages, cargo ships of 500 gross tonnages and upwards, as well as passenger
ships. It transmits typically on 12.5 watt output power.
Inland AIS
all the features of a Class A transceiver with the addition of features required for Inland
waterways.
AIS Class B:
provides limited functionality and is intended for non-SOLAS commercial vessels and
recreational vessels. It transmits typically on 2 watt output power.
AIS Base Station:
is provided by aids-to-navigation authorities to enable the ship to shore / shore to ship
transmission of information. Networked AIS Base Stations can assist in providing overall
maritime domain awareness.
AIS AtoN (Aids to Navigation):
provides an opportunity to transmit position and status of buoys and lights through the same
VDL, which can then show up on AIS-ready devices within the range.
AIS SART:
Search and Rescue Transmitter using AIS can be used to assist in determining the location of
a vessel in distress. It is typically used on life rafts.
AIS on Search and Rescue (SAR) Aircraft:
used on airplanes and helicopters to assist search and rescue operation.