Resolution A.1106(29)
Adopted on 2 December 2015
(Agenda item 10)
REVISED
GUIDELINES FOR THE ONBOARD OPERATIONAL USE OF SHIPBORNE AUTOMATIC
IDENTIFICATION SYSTEMS (AIS)
THE ASSEMBLY,
RECALLING Article 15(j) of the Convention on the International
Maritime Organization concerning the functions of the Assembly in relation to
regulations and guidelines concerning maritime safety,
RECALLING ALSO the provisions of regulation V/19 of the
International Convention for the Safety of Life at Sea (SOLAS), 1974, as
amended, requiring all ships of 300 gross tonnage and upwards engaged on
international voyages, cargo ships of 500 gross tonnage and upwards not engaged
on international voyages and passenger ships irrespective of size to be fitted
with an automatic identification system (AIS), as specified in SOLAS regulation
V/19.2.4, taking into account the recommendations adopted by the Organization,
RECALLING FURTHER resolution A.917(22), as amended by resolution A.956(23), by which
it adopted Guidelines for the onboard operational use of shipborne automatic
identification systems (AIS),
HAVING CONSIDERED the recommendations made by the Maritime Safety
Committee at its ninety-fourth session,
1 ADOPTS the Revised
guidelines for the onboard operational use of shipborne automatic
identification systems (AIS), set out in the annex to the present
resolution;
2 INVITES
Governments concerned to take into account the annexed revised guidelines when
implementing SOLAS regulations V/11, 12 and 19;
3 ALSO INVITES
Governments which are considering setting or have set regional frequencies or
otherwise make use of AIS channel management, including changing to narrow-band
operation for whatever reason, to take into account the possible impact on the
use of AIS at sea and that it should only be used for urgent temporary
situations. In such cases Governments should notify the Organization of such
areas and designated frequencies, for urgent circulation of that information to
all Member Governments;
4 REQUESTS the
Maritime Safety Committee to keep the revised guidelines under review and amend
them as appropriate;
5 REVOKES
resolution A.917(22),
as amended by resolution A.956(23).
Annex
REVISED GUIDELINES FOR THE ONBOARD OPERATIONAL USE OF SHIPBORNE
AUTOMATIC IDENTIFICATION SYSTEMS (AIS)
PURPOSE
1 These Guidelines
have been developed to promote the safe and effective use of shipborne Automatic
Identification Systems (AIS), in particular to inform the mariner about the
operational use, limits and potential uses of AIS. Consequently, AIS should be
operated taking into account these Guidelines.
2 Before using
shipborne AIS, the user should fully understand the principle of the current
Guidelines and become familiar with the operation of the equipment, including
the correct interpretation of the displayed data. A description of the AIS
system, particularly with respect to shipborne AIS (including its components
and connections), is contained in annex 1.
|
CAUTION Not all ships carry AIS. The officer of the watch (OOW) should always be aware that other
ships, in particular leisure craft, fishing boats and warships, and some
coastal shore stations including Vessel Traffic Service (VTS) centres, might
not be fitted with AIS. The OOW should always be aware that AIS fitted on other ships as
a mandatory carriage requirement might, under certain circumstances, be
switched off on the master's professional judgement. |
3 The
internationally-adopted shipborne carriage requirements for AIS are contained
in SOLAS regulation V/19. The SOLAS Convention requires AIS to be fitted on
certain ships through a phased implementation period spanning from 1 July 2002
to 1 July 2008. In addition, specific ship types (e.g. warships, naval
auxiliaries and ships owned/operated by Governments) are not required to be
fitted with AIS. Also, small ships (e.g. leisure craft, fishing boats) and
certain other ships may be exempt from carrying AIS. Moreover, ships fitted
with AIS might have the equipment switched off. Users are therefore cautioned
always to bear in mind that information provided by AIS may not be giving a
complete or correct "picture" of shipping traffic in their vicinity.
The guidance in this document on the inherent limitations of AIS and their use
in collision avoidance situations (see paragraphs 40 to 44) should therefore be
observed.
Objectives of AIS
4 AIS is intended
to enhance: safety of life at sea; the safety and efficiency of navigation; and
the protection of the marine environment. SOLAS regulation V/19 requires that
AIS exchange data ship-to-ship and with shore-based facilities. Therefore, the
purpose of AIS is to help identify ships, assist in target tracking, assist
in search and rescue operation, simplify information exchange (e.g. reduce
verbal mandatory ship reporting) and provide additional information to assist
situation awareness. In general, data received via AIS will improve the quality
of the information available to the OOW, whether at a shore surveillance
station or on board a ship. AIS is a useful source of supplementary information
to that derived from navigational systems (including radar) and therefore an
important 'tool' in enhancing situation awareness of traffic confronting users.
DESCRIPTION OF AIS
Figure 1 – AIS system overview
5 Class A shipborne
equipment complies with relevant IMO AIS carriage requirement. Class B
shipborne equipment provides functionalities not in full accordance with IMO
AIS carriage requirement. Class B devices may be carried on ships which are not
subject to the SOLAS carriage requirements.
6 Shipborne AIS
(see figure 1):
- transmits ship's own
data to other ships and vessel traffic service (VTS) stations; and
- receives and makes
available data of other ships and VTS stations and other AIS stations, such as
AIS-SARTs, AIS-ATON, etc.
7 When used with the
appropriate display, shipborne AIS enables provision of fast, automatic
information by calculating Closest Point of Approach (CPA) and Time to Closest
Point of Approach (TCPA) from the position information transmitted by the
target vessels.
8 AIS operates
primarily on two dedicated VHF channels. Where these channels are not available
regionally, the AIS is capable of being automatically switched to designated
alternate channels by means of a message from a shore facility. Where no
shore-based AIS or Global Maritime Distress and Safety System (GMDSS) Sea Area
A1 station is in place, the AIS should be switched manually. However, this
capability should only be considered for use in urgent, temporary situations,
noting the possible adverse effects on AIS at sea.
9 The capacity of
the system allows for a great number of ships to be accommodated at the same
time. Priority in the system is given to Class A devices. Class B devices
operate at a reduced reporting rate or when free time slots are available.
10 The AIS is able to
detect ships within VHF/FM range around bends and behind islands, if the
landmasses are not too high. A typical value to be expected at sea is 20 to 30
nautical miles depending on antenna height. With the help of repeater stations,
the coverage for both ship and VTS stations can be improved.
11 Information from a
shipborne AIS is transmitted continuously and automatically without any
intervention or knowledge of the OOW. An AIS shore station might require
updated information from a specific ship by "polling" that ship, or
alternatively, might wish to "poll" all ships within a defined sea
area. However, the shore station can only increase the ships' reporting rate,
not decrease it.
AIS INFORMATION SENT BY SHIPS
Ship's
data content
12 The AIS
information transmitted by a ship is of three different types:
- static information,
which is entered into the AIS on installation and need only be changed if the
ship changes its name, Maritime Mobile Service Identity (MMSI), location of the
electronic position fixing system (EPFS) antenna, or undergoes a major
conversion from one ship type to another;
- dynamic information,
which, apart from "Navigational status" information, is
automatically updated from the ship sensors connected to AIS; and
- voyage-related
information, which might need to be manually entered and updated during the
voyage.
13 Details of the
information referred to above are given in table 1 below:
|
Information item |
Information generation, type and quality of information |
|
Static |
|
|
MMSI
|
Set
on installation Note
that this might need amending if the ship changes ownership |
|
Call
sign and name |
Set
on installation Note
that this might need amending if the ship changes ownership |
|
IMO
Number |
Set
on installation |
|
Length
and beam |
Set
on installation or if changed |
|
Type
of ship |
Select
from pre-installed list |
|
Location
of electronic position
fixing system (EPFS) antenna |
Set on installation or may be changed for bi-directional vessels
or those fitted with multiple antennas |
|
Dynamic
|
|
|
Ship's
position with accuracy indication and integrity status |
Automatically
updated from the position sensor connected to AIS The accuracy indication is
approximately 10 m. |
|
Position
Time stamp in UTC
|
Automatically updated from ship's main position sensor connected
to AIS |
|
Course over ground
(COG) |
Automatically
updated from ship's main position sensor connected to AIS, if that sensor
calculates COG This information might not be available |
|
Speed
over ground (SOG) |
Automatically updated from the position sensor connected to AIS.
This information might not be available |
|
Heading
|
Automatically updated from the ship's heading sensor connected
to AIS |
|
Navigational
status |
Navigational status information has to be manually entered by
the OOW and changed as necessary, for example: - underway by engines - at anchor - not under command (NUC) - restricted in ability to manoeuvre
(RIATM) - moored - constrained by draught - aground - engaged in fishing - underway by sail In
practice, since all these relate to the COLREGs, any change that is needed
could be undertaken at the same time that the lights or shapes were changed |
|
Rate
of turn (ROT) |
Automatically updated from the ship's ROT sensor or derived from
the gyro. This
information might not be available |
|
Voyage-related
|
|
|
Ship's
draught |
To
be manually entered at the start of the voyage using the maximum draft for
the voyage and amended as required (e.g. – result of de-ballasting prior to
port entry) |
|
Hazardous
cargo (type) |
To be manually entered at the start of the voyage confirming
whether or not hazardous cargo is being carried, namely: - DG (Dangerous goods) - HS (Harmful substances) - MP (Marine pollutants) Indications
of quantities are not required |
|
Destination
and ETA |
To be manually entered at the start of the voyage and kept up to
date as necessary |
|
Route
plan (waypoints) |
To
be manually entered at the start of the voyage, at the discretion of the
master, and updated when required |
|
Safety-related
|
|
|
Short
safety-related messages |
Free
format short text messages would be manually entered, addressed either a
specific addressee or broadcast to all ships and shore stations |
Table
1 – Data sent by ship
* Due to the amendment
of MARPOL categorization of hazardous cargo by resolution MEPC.118(52),
cargo type may be categorized as A, B, C or D, rather than X, Y, Z or OS on
older AIS equipment, as described in SN.1/Circ.227 and SN.1/Circ.227/Corr.1.
The
table below indicates the equivalence of the old and new category indications:
|
Current MARPOL category |
Equivalent category on older AIS units |
|
X |
A |
|
Y |
B |
|
Z |
C |
|
OS |
D |
14 The data is
autonomously sent at different update rates:
- dynamic information:
dependent on speed and course alteration (see tables 2 and 3);
- static and
voyage-related data: every 6 minutes or on request (AIS responds automatically
without user action); and
- safety-related text
message: as required.
|
Type
of ship |
General reporting interval |
|
Ship
at anchor or moored and not moving faster than 3 knots |
3 min |
|
Ship
at anchor or moored and moving faster than 3 knots |
10 s |
|
Ship
0-14 knots |
10 s |
|
Ship
0-14 knots and changing course |
3 1/3 s |
|
Ship
14-23 knots |
6 s |
|
Ship
14-23 knots and changing course |
2 s |
|
Ship
>23 knots |
2 s |
|
Ship
>23 knots and changing course |
2 s |
Table 2 – Class A shipborne equipment reporting intervals
|
Crafts not subject to SOLAS |
Nominal reporting interval |
|
Class
B "SO" shipborne equipment not moving faster than 2 knots |
3 min |
|
Class
B "SO" shipborne equipment moving 2-14 knots |
30 s |
|
Class
B "SO" shipborne equipment moving 14-23 knots |
15 s |
|
Class
B "SO" shipborne equipment moving ˃ 23 knots |
5 s |
|
Class
B "CS" shipborne equipment not moving faster than 2 knots |
3 min |
|
Class
B "CS" shipborne equipment moving faster than 2 knots |
30 s |
Table
3 – Class B shipborne equipment reporting intervals
Short safety-related
messages
15 Short
safety-related messages are fixed or free format text messages addressed either
to a specified destination (MMSI) or all ships in the area. Their content
should be relevant to the safety of navigation, e.g. an iceberg sighted or a
buoy not on station. Messages should be kept as short as possible. The system
allows up to 158 characters per message but the shorter the message the more easily
it will find free space for transmission. At present these messages are not
further regulated, to keep all possibilities open.
16 Operator
acknowledgement may be requested by a text message. The operator should be
aware that there are special safety-related messages and special user
identities form devices such as the AIS-SART. Details are given in
SN.1/Circ.322, as amended. There is no need for acknowledgement by a text
message.
17 Short
safety-related messages are only an additional means of broadcasting maritime
safety information. Whilst their importance should not be underestimated, use
of such messages does not remove any of the requirements of the GMDSS.
18 The operator should
ensure that he displays and considers incoming safety-related messages and
should send safety-related messages as required.
19 According to SOLAS
regulation V/31 (Danger messages)
"The
master of every ship which meets with dangerous ice, a dangerous derelict, or
any other direct danger to navigation, or ...is bound to communicate the
information by all the means at his disposal to ships at his vicinity, and also
to the competent authorities..."
20 Normally this is
done via VHF voice communication, but "by all the means" now implies
the additional use of the AIS short messages application, which has the
advantage of reducing difficulties in understanding, especially when noting
down the correct position.
Confidentiality
21 When entering any
data manually, consideration should be given to the confidentiality of this
information, especially when international agreements, rules or standards
provide for the protection of navigational information.
OPERATION OF AIS ON BOARD
OPERATION OF THE
TRANSCEIVER UNIT
Activation
22 AIS should always
be in operation when ships are underway or at anchor. If the master believes
that the continual operation of AIS might compromise the safety or security of
his/her ship or where security incidents are imminent, the AIS may be switched
off. Unless it would further compromise the safety or security, if the ship is
operating in a mandatory ship reporting system, the master should report this
action and the reason for doing so to the competent authority. Actions of this
nature should always be recorded in the ship's logbook together with the reason
for doing so. The master should however restart the AIS as soon as the source
of danger has disappeared. If the AIS is shut down, static data and
voyage-related information remains stored. Restart is done by switching on the power
to the AIS unit. Ship's own data will be transmitted after a two-minute
initialization period. In ports AIS operation should be in accordance with port
requirements.
Manual input of data
23 The OOW should
manually input the following data at the start of the voyage and whenever
changes occur, using an input device such as a keyboard:
- ship's draught;
- hazardous cargo;
- departure, destination
and ETA;
- route plan (way
points);
- the correct
navigational status; and
- short safety-related
text messages.
It is recommended to use the United Nations Code for Trade and
Transport Locations (UN/LOCODE) for the entry of the port of destination. In
addition, it is recommended that the existing destination field be used for
entering both the port of departure and the next port of call (space for 20
characters of 6 bit ASCII is available) using the UN/LOCODE.1
__________________
1 SN/Circ.244.
Check of information
24 To ensure that
own ship's static information is correct and up-to-date, the OOW should check
the data whenever there is a reason for it. As a minimum, this should be done
once per voyage or once per month, whichever is shorter. The data may be
changed only on the authority of the master.
25 The OOW should
also periodically check the following dynamic information:
- positions given
according to WGS 84;
- speed over ground; and
- sensor information.
26 After activation,
an automatic built-in integrity test (BIIT) is performed. In the case of any
AIS malfunction an alarm is provided and the unit should stop transmitting.
27 The quality or
accuracy of the ship sensor data input into AIS would not however be checked by
the BIIT circuitry before being broadcast to other ships and shore stations.
The ship should therefore carry out regular routine checks during a voyage to
validate the accuracy of the information being transmitted. The frequency of
those checks would need to be increased in coastal waters.
DISPLAY OF AIS DATA
28 The AIS provides
data that can be presented on the minimum display or on any suitable display
device, as described in annex 1.
Minimum display
29 The minimum
mandated display provides not less than three lines of data consisting of
bearing, range and name of a selected ship. Other data of the ship can be
displayed by horizontal scrolling of data, but scrolling of bearing and range
is not possible. Vertical scrolling will show all the other ships known to the
AIS.
Graphical display
30 Where AIS
information is used with a graphical display, the following target types may be
displayed:
|
Sleeping
target |
A
sleeping target indicates only the presence of a vessel equipped with AIS in
a certain location. No additional information is presented until activated,
thus avoiding information overload. |
|
Activated
target |
If the user wants to know more about a vessel's motion, the
target (sleeping) may be activated so that the display shows immediately: - a vector (speed and course over ground);
- the heading; and - ROT indication (if available) to display
actually initiated course changes. |
|
Selected
target |
If
the user wants detailed information on a target (activated or sleeping), it
may be selected. Then the data received, as well as the calculated CPA and
TCPA values, will be shown in an alpha-numeric window. The special navigation status will also be indicated in the
alpha numeric data field and not together with the target directly. |
|
Dangerous
target |
If
an AIS target (activated or not) is calculated to pass preset CPA and TCPA
limits, it will be classified and displayed as a dangerous target and an
alarm will be given. |
|
Lost
target |
If
a signal of any AIS target at a distance of less than a preset value is not
received, a lost target symbol will appear at the latest position and an
alarm will be given. |
|
Other
targets |
Other
targets such as AIS-SART, AIS-AToN, may be displayed with special symbols
(see SN.1/Circ.243/Rev.1 on Guidelines for the presentation of
navigational-related symbols, terms and abbreviations). |
Symbols
31 The user should be
familiar with the symbology used in the graphical display provided.
INHERENT LIMITATIONS
OF AIS
32 The OOW should
always be aware that other ships, in particular leisure craft, fishing boats
and warships, and some coastal shore stations including VTS centres, might not
be fitted with AIS.
33 The OOW should
always be aware that other ships fitted with AIS as a mandatory carriage
requirement might switch off AIS under certain circumstances by professional
judgement of the master.
34 In other words, the
information given by the AIS may not be a complete picture of the situation
around the ship.
35 The users must be
aware that transmission of erroneous information implies a risk to other ships
as well as their own. The users remain responsible for all information entered
into the system and the information added by the sensors.
36 The accuracy of AIS
information received is only as good as the accuracy of the AIS information
transmitted.
37 The OOW should be
aware that poorly configured or calibrated ship sensors (position, speed and
heading sensors) might lead to incorrect information being transmitted.
Incorrect information about one ship displayed on the bridge of another could
be dangerously confusing.
38 If no sensor is
installed or if the sensor (e.g. the gyro) fails to provide data, the AIS
automatically transmits the "not available" data value. However, the
built-in integrity check cannot validate the contents of the data processed by
the AIS.
39 It would not be
prudent for the OOW to assume that the information received from other ships is
of a comparable quality and accuracy to that which might be available on its
own ship.
USE OF AIS IN COLLISION AVOIDANCE SITUATIONS
40 The potential of
AIS as an assistance for anti-collision device is recognized and AIS may be
recommended as such a device in due time.
41 Nevertheless, AIS
information may merely be used to assist in collision avoidance
decision-making. When using the AIS in the ship-to-ship mode for anti-collision
purposes, the following cautionary points should be borne in mind:
.1 AIS is an additional source of navigational
information. It does not replace, but supports, navigational systems such as
radar target-tracking and VTS; and
.2 the
use of AIS does not negate the responsibility of the OOW to comply at all times
with the Collision Regulations, particularly rule 7 when determining whether
risk of collisions exists.
42 The user should not
rely on AIS as the sole information system, but should make use of all
safety-relevant information available.
43 The use of AIS on
board ship is not intended to have any special impact on the composition of the
navigational watch, which should continue to be determined in accordance with
the STCW Convention.
44 Once a ship has
been detected, AIS can assist in tracking it as a target. By monitoring the
information broadcast by that target, its actions can also be monitored. Many
of the problems common to tracking targets by radar, namely clutter, target
swap as ships pass close by and target loss following a fast manoeuvre, do not
affect AIS. AIS can also assist in the identification of targets, by name or
call sign and by ship type and navigational status.
ADDITIONAL AND POSSIBLE
FUTURE APPLICATIONS
AIS IN VTS OPERATIONS
Pseudo Targets broadcast by
VTS
45 VTS centres may
send information about vessels which are not carrying AIS and which are tracked
only by VTS radar via the AIS to vessels equipped with AIS. Any VTS/generated/synthetic
target broadcast by VTS should be clearly identified as such. Particular care
should always be taken when using information which has been relayed by a third
party. Accuracy of these targets may not be as complete as actual directly-received
targets, and the information content may not be as extensive.
Text messages
46 VTS centres may
also send short messages either to one ship, all ships, or ships within a
certain range or in a special area, e.g.:
- (local) navigational
warnings;
- traffic management
information; and
- port management
information.
47 A VTS operator
may request, by a text message, an acknowledgement from the ship's operator.
Note: The
VTS should continue to communicate via voice VHF. The importance of verbal
communication should not be underestimated. This is important to enable the VTS
operator to:
- assess vessels'
communicative ability; and
- establish a direct
communication link which would be needed in critical situations.
(D)GNSS corrections
48 (D)GNSS
corrections may be sent by VTS centres via AIS.
MANDATORY SHIP
REPORTING SYSTEMS
49 AIS is expected to
play a major role in ship reporting systems. The information required by
coastal authorities in such systems is typically included in the static
voyage-related and dynamic data automatically provided by the AIS system. The
use of the AIS long-range feature, where information is exchanged via
communications satellite, may be implemented to satisfy the requirements of
some ship reporting systems.
AIS IN SAR OPERATIONS
50 AIS may be used in
search and rescue operations. By receiving messages from AIS-SART, operators
get more accurate information, especially on the position of survival craft. In
combined aerial and surface searches AIS may allow the direct presentation of
the position on other displays such as radar or ECS/ECDIS, which facilitates
the task of SAR craft. For ships in distress without AIS, the On Scene
Coordinator (OSC) could create an AIS target.
AIDS TO NAVIGATION
51 AIS, when fitted to
selected fixed and floating aids to navigation can provide information to the
mariner such as:
- position;
- status;
- tidal and current
data; and
- weather and visibility
conditions.
AIS IN AN OVERALL
INFORMATION SYSTEM
52 AIS will play a
role in an overall international maritime information system, supporting voyage
planning and monitoring. This will help Administrations to monitor all the
vessels in their areas of concern and to track dangerous cargo.
REFERENCE
DOCUMENTS
- SOLAS Convention,
chapter V
- Recommendation on
performance standards for a universal shipborne Automatic Identification System
(AIS), (MSC.74(69),
annex 3)
- Performance Standards
for survival craft AIS search and rescue transmitters (AIS-SART) for use in
search and rescue operations (resolution MSC.246(83))
- Guidance on the use of
the UN/LOCODE in the destination field in AIS messages (SN/Circ.244)
- ITU Radio Regulations,
appendix 18, table of transmitting frequencies in the VHF maritime mobile band
- Technical
characteristics for an automatic identification system using time division
multiple access in the VHF maritime mobile frequency band (Recommendation ITU-R
M.1371-5)
- IEC Standard 61993
Part 2: Class A shipborne equipment of the Universal Shipborne Automatic
Identification System (AIS) Operational and Performance Requirements, Methods
of Testing and required Test Results
APPENDIX 1
DESCRIPTION OF AIS
COMPONENTS
1 In general, an
onboard AIS (see figure 1) consists of:
- antennas;
- one VHF transmitter;
- two multi-channel VHF
receivers;
- one channel 70 VHF
receiver for channel management;
- a central processing
unit (CPU);
- an electronic
position-fixing system, Global Navigation Satellite System (GNSS) receiver for
timing purposes and position redundancy;
- interfaces to heading
and speed devices and to other shipborne sensors;
- interfaces to
radar/Automatic Radar Plotting Aids (ARPA), Electronic Chart System/Electronic
Chart Display and Information System (ECS/ECDIS) and Integrated Navigation
Systems (INS);
- built-in integrity
test (BIIT); and
- minimum display and
keyboard to input and retrieve data.
With the integral minimum display and keyboard unit, the AIS would
be able to operate as a stand-alone system. A stand-alone graphical display or
the integration of the AIS data display into other devices such as INS,
ECS/ECDIS or a radar/ARPA display would significantly increase the
effectiveness of AIS, when achievable.
2 All onboard
sensors must comply with the relevant IMO standards concerning availability,
accuracy, discrimination, integrity, update rates, failure alarms, interfacing
and type-testing.