This is a prototype of what the web front end to the AIS Binary Message registry might look like in html web form. The registry would be represented as an XML file containing all known binary messages from the IMO and all local authories with DAC codes. Countries can then reuse messages from other countries' regional authorities, thereby limiting the total number of binary messages needed for the whole world.

This contains just a few example messages from IMO, the European River Information System (ris) project, and the North American Saint Lawrence Seaway (sls).

-Kurt Schwehr, Feb 2008

AIS Binary Message Definitions

AIS Message: imo_met_hydro (001:11)

Description:

IMO meteorological and hydroglogical data. Specified in SN/Circ.236 Annex 2. Also defined in IALA Guidelines on AIS, Vol 1, Part 1, Ed. 1.3. Guildeline No 1028.

Note:All unavailable values are defined to be the highest possible number in the next following

Name NumberOfBits ArrayLength Type Units Description
MessageID 6 uint AIS message number. Must be 8
RepeatIndicator 2 uint Indicated how many times a message has been repeated
0: default
3: do not repeat any more
UserID 30 uint MMSI number of transmitter broadcasting the message
Spare 2 uint Reserved for definition by a regional authority.
dac 10 uint Designated Area Code - part 1 of the IAI
fid 6 uint Functional Identifier - part 2 of the IAI
latitude 24 decimal degrees Location of the vessel. North South location
longitude 25 decimal degrees Location of the vessel. East West location
day 5 uint days Day 0..31
hour 5 uint hours Hour 0..23
min 6 uint minutes Min
avewind 7 uint knots Average wind speed values for the last 10 minutes.
windgust 7 uint knots Wind gust is the max wind speed value reading during the last 10 minutes.
winddir 9 uint degrees Wind direction
windgustdir 9 uint degrees Wind direction for the gust.
airtemp 11 decimal degrees Celsius Dry bulb temperature
relhumid 7 uint percent Relative humidity
dewpoint 10 decimal degrees Celsius Dew Point
airpressure 9 udecimal hPa Air pressure
airpressuretrend 2 uint Air pressure trend
0: steady
1: decreasing
2: increasing
3: unavailable
horizvis 8 udecimal nm Horizontal visibility
waterlevel 9 decimal m Water level (incl. tide)
waterleveltrend 2 uint Water level trend
0: steady
1: decreasing
2: increasing
3: unavailable
surfcurspeed 8 udecimal knots Surface current speed
surfcurdir 9 uint degrees Surface current direction
curspeed2 8 udecimal knots Level 2 current speed
curdir2 9 uint degrees Level 2 current direction
curlevel2 5 uint m Measuring level below sea surface for level 2
curspeed3 8 udecimal knots Level 3 current speed
curdir3 9 uint degrees Level 3 current direction
curlevel3 5 uint m Measuring level below sea surface for level 3
sigwaveheight 8 udecimal m Significant wave height
waveperiod 6 uint sec Wave period
wavedir 9 uint degrees Wave direction
swellheight 8 udecimal m Swell height
swellperiod 6 uint sec Swell period
swelldir 9 uint degrees Swell direction
seastate 4 uint Beaufort scale Sea state according to the Beaufort scale
0: Calm
1: Light air
2: Light breeze
3: Gentle breeze
4: Moderate breeze
5: Fresh breeze
6: Strong breeze
7: Near gale
8: Gale
9: Strong gale
10: Storm
11: Violent storm
12: Hurricane
15: unavailable
watertemp 10 udecimal degrees Celsius Water temperature
preciptype 3 uint WMO scale index According to WMO
0: FIX: find the WMO list of types
7: unavailable
salinity 9 decimal 0/00 Salinity
ice 2 uint Yes or no for the presence of ice
0: Not sure. Maybe no ice?
1: Not sure. Maybe yes ice?
2: Not sure. Maybe not allowed?
3: Unknown?
Spare 6 uint Must be zero

AIS Message: imo_fairway_closed (001:13:)

Description:

IMO fairway closed. Specified in SN/Circ.236 Annex 2, page 4, Application 3. Also defined in IALA Guidelines on AIS, Vol 1, Part 1, Ed. 1.3. Guildeline No 1028. This message should be used to inform ships, in particular to give guidance to large vessels about temporary closed fairways or sections in ports. Attributes: broadcast, shore station transmitting, no acknowledgement.

Name NumberOfBits ArrayLength Type Units Description
MessageID 6 uint AIS message number. Must be 8
RepeatIndicator 2 uint Indicated how many times a message has been repeated
0: default
3: do not repeat any more
UserID 30 uint MMSI number of transmitter broadcasting the message
Spare 2 uint Reserved for definition by a regional authority.
dac 10 uint Designated Area Code - part 1 of the IAI
fid 6 uint Functional Identifier - part 2 of the IAI
reason 6 20 aisstr6 Reason for closing
from 6 20 aisstr6 Location of closing from
to 6 20 aisstr6 Location of closing To
radius 10 uint See unit field Extention of closed area
unit 2 uint Unit of extension value for range field
0: m
1: km
2: nm
3: cbl
closingday 5 uint Closing from day
closingmonth 4 uint Closing from month
fromhour 5 uint From LT hour (appr)
frommin 6 uint From LT minute (appr)
today 5 uint To day
tomonth 4 uint To month
tohour 5 uint To LT hour (appr)
tomin 6 uint To LT minute (appr)
spare2 4 uint Padding out the slot

AIS Message: imo_tidal_window (001:13:)

Description:

IMO fairway closed. Specified in SN/Circ.236 Annex 2, page 5, Application 3. Also defined in IALA Guidelines on AIS, Vol 1, Part 1, Ed. 1.3. Guildeline No 1028. This message should be used to inform vessels about tidal windows which allow a vessel the safe passage of a fairway. The message includes predictions of current speed and current direction. In this example, three points of tidal information are given. Attributes of message: addressed, shore station transmitting, acknowledgement required.

Name NumberOfBits ArrayLength Type Units Description
MessageID 6 uint AIS message number. Must be 6
RepeatIndicator 2 uint Indicated how many times a message has been repeated
0: default
3: do not repeat any more
UserID 30 uint MMSI number of transmitter broadcasting the message
SeqNum 2 uint Sequence number as described in 5.3.1. Assigned to each station
DestinationID 30 uint Unique ship identification number (MMSI)
RetransmitFlag 1 bool Should be set upon retransmission
0: no retransmission
1: restransmitted
Spare 1 uint Must be 0
dac 10 uint Designated Area Code - part 1 of the IAI
fid 6 uint Functional Identifier - part 2 of the IAI
month 4 uint UTC month
day 5 uint UTC day
window1_longitude 28 decimal degrees Not sure what this position is for? Center? East West location
window1_latitude 27 decimal degrees Not sure what this position is for? Center? North South location
fromhour1 5 uint hours From UTC hour
frommin1 6 uint minutes From UTC minute
tohour1 5 uint hours To UTC hour
tomin1 6 uint minutes To UTC minute
curdir1 9 uint degrees Current direction
curspeed1 7 udecimal knots Current speed
window2_longitude 28 decimal degrees Not sure what this position is for? Center? East West location
window2_latitude 27 decimal degrees Not sure what this position is for? Center? North South location
fromhour2 5 uint hours From UTC hour
frommin2 6 uint minutes From UTC minute
tohour2 5 uint hours To UTC hour
tomin2 6 uint minutes To UTC minute
curdir2 9 uint degrees Current direction
curspeed2 7 udecimal knots Current speed
window3_longitude 28 decimal degrees Not sure what this position is for? Center? East West location
window3_latitude 27 decimal degrees Not sure what this position is for? Center? North South location
fromhour3 5 uint hours From UTC hour
frommin3 6 uint minutes From UTC minute
tohour3 5 uint hours To UTC hour
tomin3 6 uint minutes To UTC minute
curdir3 9 uint degrees Current direction
curspeed3 7 udecimal knots Current speed

AIS Message: ris_waterlevel (000:24:)

Description:

RIS ECE/TRANS/SC.3/2006/10 Table 2.15: Water level report

Name NumberOfBits ArrayLength Type Units Description
MessageID 6 uint AIS message number. Must be 8
RepeatIndicator 2 uint Indicated how many times a message has been repeated
0: default
3: do not repeat any more
UserID 30 uint Unique ship identification number (MMSI)
Spare 2 uint Reserved for definition by a regional authority.
dac 10 uint Designated Area Code
fid 6 uint Functional Identifier
country 6 2 aisstr6 UN country code using 2*6-Bit ASCII characters according to ERI specification
id1_id 11 uint One tide gauge measurement. Station ID defined by ERI for each country
id1_sign 1 uint One tide gauge measurement. sign of the number in the waterlevel
0: -1
1: 1
id1_waterlevel 11 decimal m One tide gauge measurement. Water level at the sensor
id1_i_have_no_idea 2 uint One tide gauge measurement. What are these bits for? They do not seem to be specified
id2_id 11 uint One tide gauge measurement. Station ID defined by ERI for each country
id2_sign 1 uint One tide gauge measurement. sign of the number in the waterlevel
0: -1
1: 1
id2_waterlevel 11 decimal m One tide gauge measurement. Water level at the sensor
id2_i_have_no_idea 2 uint One tide gauge measurement. What are these bits for? They do not seem to be specified
id3_id 11 uint One tide gauge measurement. Station ID defined by ERI for each country
id3_sign 1 uint One tide gauge measurement. sign of the number in the waterlevel
0: -1
1: 1
id3_waterlevel 11 decimal m One tide gauge measurement. Water level at the sensor
id3_i_have_no_idea 2 uint One tide gauge measurement. What are these bits for? They do not seem to be specified
id4_id 11 uint One tide gauge measurement. Station ID defined by ERI for each country
id4_sign 1 uint One tide gauge measurement. sign of the number in the waterlevel
0: -1
1: 1
id4_waterlevel 11 decimal m One tide gauge measurement. Water level at the sensor
id4_i_have_no_idea 2 uint One tide gauge measurement. What are these bits for? They do not seem to be specified

AIS Message: sls_waterlevel (366 316:1:3)

Description:

St Lawrance Seaway water level message

Name NumberOfBits ArrayLength Type Units Description
time_month 4 uint Time tag of measurement month 1..12
time_day 5 uint Time tag of measurement day of the month 1..31
time_hour 5 uint Time tag of measurement UTC hours 0..23
time_min 6 uint Time tag of measurement minutes
stationid 6 7 aisstr6 Character identifier of the station. Usually a number.
pos_longitude 25 decimal degrees Location of measurement East West location
pos_latitude 24 decimal degrees Location of measurement North South location
type 1 uint How to interpret the water level
0: Relative to datum
1: Water depth
waterlevel 16 int cm Water level in centimeters
datum 2 uint What reference datum applies to the value
0: MLLW
1: IGLD-85
2: Reserved
3: Reserved
reserved 14 uint Reserved bits for future use

AIS Message: sls_weatherreport (366 316:1:2)

Description:

St Lawrance Seaway wind information

Name NumberOfBits ArrayLength Type Units Description
time_month 4 uint Time tag of measurement month 1..12
time_day 5 uint Time tag of measurement day of the month 1..31
time_hour 5 uint Time tag of measurement UTC hours 0..23
time_min 6 uint Time tag of measurement minutes
stationid 6 7 aisstr6 Character identifier of the station
pos_longitude 25 decimal degrees Location of measurement East West location
pos_latitude 24 decimal degrees Location of measurement North South location
speed 10 udecimal kts Average wind speed
102.2: 102.2 kts or greater
gust 10 udecimal kts Wind gust
102.2: 102.2 kts or greater
direction 9 uint degrees Wind direction
atmpressure 14 udecimal millibars Atmospheric pressure
airtemp 10 decimal Celsius Air temperature
-51.1: -51.1 degrees C or lower
51.1: 51.1 degrees C or greater
dewpoint 10 decimal Celsius Dew Point
-51.1: -51.1 degrees C or lower
51.1: 51.1 degrees C or greater
visibility 8 udecimal km Visibility
25.4: 25.4 km or greater
watertemp 10 decimal Celsius Water Temperature
-51.1: -51.1 degrees C or lower
51.1: 51.1 degrees C or greater
reserved 4 uint Reserved bits for future use