Combined data extracts

Spire Maritime AIS data extracts are normally provided in CSV format with data fields as listed in the table of data fields below. In the combined data extract format, Spire Maritime have processed the AIS messages per MMSI and joined together the most recently reported Static values with each new position message. This provides a per vessel view of AIS history based on the MMSI number.

Different AIS messages

AIS History data for vessels contains data from two different types of AIS messages: position messages and static voyage messages:

• Message Types 1, 2, 3, 18, 19, 27 are some common position messages that contain values in the position related fields, such as speed, heading, rate of turn, position, and status of vessels.
• Message Types 5 & 24 are static voyage messages and contain values in the static details and voyage related fields, such as identity, type, size and voyage information.

In this format we process the AIS messages per MMSI and join together the most recently reported Static values with each new position message, using the MMSI number as the join between them. For example – to identify the name, imo number, or type of ships related to the AIS Position reports, the mmsi number must be used to join together the 2 different sets of AIS data. So if position reports are recorded against MMSI 636018333 in AIS message type 1, then the imo and name of that vessel is discovered by looking for AIS message type 5 reported using the same MMSI number as shown below:

More information on AIS Message Types can be found in the Spire Maritime’s AIS Fundamentals article on AIS Message Types.

Data columns description

created_at datetime

ISO 8601 formatted timestamp in UTC of the time the vessel record was merged to create combined information

timestamp datetime

ISO 8601 formatted timestamp in UTC of the time the AIS message was transmitted

static_updated_at datetime

ISO 8601 formatted timestamp in UTC of the time the last AIS static message was received

position_updated_at datetime

ISO 8601 formatted timestamp in UTC of the time the last AIS position message was received

mmsi integer

The Maritime Mobile Service Identity of the vessel transmitting the AIS message

Possible values: 000000000 – 999999999

latitude float

Vessel latitude in degrees (North=positive, South=negative)

Range: -90 to +90

longitude float

Vessel longitude in degrees (East = positive, West=negative)

Range: -180 to +180

speed number

Vessel speed over ground represented in knots

Possible values: 0 - 102.2 knots, 102.3 (not available)

course number

Vessel course over ground in degrees

Possible values: 0 - 359.9 degrees, 360.0 (not available)

heading number

Vessel true heading in degrees

Possible values: 0 - 359 degrees, 511 (not available)

imo integer

IMO number of the ship

Unique International Maritime Organization number for the vessel that stays with the ship for it’s life

Valid values: 7 digit number

name string

Vessel name

call_sign string

Vessel call sign

flag string

Vessel flag

draught float

Vessel draught represented in 1/10 meters

Possible values: 0.1 – 255, 0 (not available; default)

ship_and_cargo_type integer

Vessel ship and cargo type code

Some common values: 30 (fishing vessel), 52 (tug boat), 70 (cargo/fishing ship) (read our AIS Essentials article on determining a ship type)

length number

Vessel length extracted from ship dimensions to_bow and to_stern in meters

width number

Vessel width extracted from ship dimensions to_port and to_starboard in meters

eta string

Vessel estimated time of arrival as entered by the captain, represented in ISO 8601 format

Possible values: Month: 1 – 12, 0 (not available; default); Day: 1 – 31, 0 (not available; default); Hour: 0 – 23, 24 (not available; default); Minute: 0 – 59, 60 (not available; default)

destination string

Vessel destination as entered by the vessel captain

status string

Vessel navigation status

Some common values: 0 (under way using engine), 1 (at anchor), 3 (restricted maneuverability), 7 (engaged in fishing), 15 (read the AIS essentials article on navigational status for more information)

maneuver integer

Vessel maneuver code

Valid values: 0 (not available; default), 1 (not engaged in special maneuver), 2 (engaged in special maneuver)

accuracy integer

Vessel GPS geo location accuracy in meters

Possible values: 1 (high, <=10 meters); 0 (low, >10 meters, default)

rot

Vessel rate of turn

Possible values: -127 - 127; -128 (not available)

collection_type string

How the message was captured

Possible values: satellite or terrestrial or dynamic