Post by HONDAM on Oct 7, 2015 17:56:30 GMT -5
At the NMEA Expo there was a lot of hype around AIS (Automatic Identification System). A lot of the manufactures were saying that its going to be the next big thing in recreational marine electronics some even believe that because of its immense safety value that one day its going to be required on vessels of a certain size. AIS is already required on all commercial and inspected vessels. AIS has been around a long time but because of the decreasing cost and shrinking size of the units it is become increasingly available to the recreational market. Basically what AIS is, is a system that receives information vessel information over a radio signal and most units will broadcast your information as well. This information includes:
An AIS transceiver sends the following data every 2 to 10 seconds depending on a vessel's speed while underway, and every 3 minutes while a vessel is at anchor:
The vessel's Maritime Mobile Service Identity (MMSI) – a unique nine digit identification number.
Navigation status – "at anchor", "under way using engine(s)", "not under command", etc.
Rate of turn – right or left, from 0 to 720 degrees per minute
Speed over ground – 0.1-knot (0.19 km/h) resolution from 0 to 102 knots (189 km/h)
Positional accuracy:
Longitude – to 0.0001 minutes
Latitude – to 0.0001 minutes
Course over ground – relative to true north to 0.1°
True heading – 0 to 359 degrees (for example from a gyro compass)
True bearing at own position. 0 to 359 degrees
UTC Seconds – The seconds field of the UTC time when these data were generated. A complete timestamp is not present.
In addition, the following data are broadcast every 6 minutes:
IMO ship identification number – a seven digit number that remains unchanged upon transfer of the ship's registration to another country
Radio call sign – international radio call sign, up to seven characters, assigned to the vessel by its country of registry
Name – 20 characters to represent the name of the vessel
Type of ship/cargo
Dimensions of ship – to nearest meter
Location of positioning system's (e.g., GPS) antenna on board the vessel - in meters aft of bow and meters port or starboard
Type of positioning system – such as GPS, DGPS or LORAN-C.
Draught of ship – 0.1 meter to 25.5 meters
Destination – max. 20 characters
ETA (estimated time of arrival) at destination – UTC month/date hour:minute
optional : high precision time request, a vessel can request other vessels provide a high precision UTC time and datestamp
So why do you want AIS? Its a piece of safety equipment. At this time its mainly going to just pick up commercial vessels but as it gains popularity more and more recreational vessels will appears. Its a compliment to radar because a lot of time there can be something between you and the other vessel preventing it from showing up on the radar but the AIS will still show it. There are entry level AIS units that only receive with an retail of under $300 (plus the cost of an antenna or splitter) and units that broadcast and receive. The units that broadcast and receive have a silent button so you don't have to give away your secret fishing spot on tourny day but other days you can leave it on. The USCG takes the AIS data it receives from its monitoring stations and broadcasts it online so if your going on a weekend trip friends and family can keep track of your progress to make sure your safe.
There a lot of different units out there that do AIS but this promotional video for the West Marine system gives a good introduction into how it works:
An AIS transceiver sends the following data every 2 to 10 seconds depending on a vessel's speed while underway, and every 3 minutes while a vessel is at anchor:
The vessel's Maritime Mobile Service Identity (MMSI) – a unique nine digit identification number.
Navigation status – "at anchor", "under way using engine(s)", "not under command", etc.
Rate of turn – right or left, from 0 to 720 degrees per minute
Speed over ground – 0.1-knot (0.19 km/h) resolution from 0 to 102 knots (189 km/h)
Positional accuracy:
Longitude – to 0.0001 minutes
Latitude – to 0.0001 minutes
Course over ground – relative to true north to 0.1°
True heading – 0 to 359 degrees (for example from a gyro compass)
True bearing at own position. 0 to 359 degrees
UTC Seconds – The seconds field of the UTC time when these data were generated. A complete timestamp is not present.
In addition, the following data are broadcast every 6 minutes:
IMO ship identification number – a seven digit number that remains unchanged upon transfer of the ship's registration to another country
Radio call sign – international radio call sign, up to seven characters, assigned to the vessel by its country of registry
Name – 20 characters to represent the name of the vessel
Type of ship/cargo
Dimensions of ship – to nearest meter
Location of positioning system's (e.g., GPS) antenna on board the vessel - in meters aft of bow and meters port or starboard
Type of positioning system – such as GPS, DGPS or LORAN-C.
Draught of ship – 0.1 meter to 25.5 meters
Destination – max. 20 characters
ETA (estimated time of arrival) at destination – UTC month/date hour:minute
optional : high precision time request, a vessel can request other vessels provide a high precision UTC time and datestamp
So why do you want AIS? Its a piece of safety equipment. At this time its mainly going to just pick up commercial vessels but as it gains popularity more and more recreational vessels will appears. Its a compliment to radar because a lot of time there can be something between you and the other vessel preventing it from showing up on the radar but the AIS will still show it. There are entry level AIS units that only receive with an retail of under $300 (plus the cost of an antenna or splitter) and units that broadcast and receive. The units that broadcast and receive have a silent button so you don't have to give away your secret fishing spot on tourny day but other days you can leave it on. The USCG takes the AIS data it receives from its monitoring stations and broadcasts it online so if your going on a weekend trip friends and family can keep track of your progress to make sure your safe.
There a lot of different units out there that do AIS but this promotional video for the West Marine system gives a good introduction into how it works: