AIS receiver & dispatcher with OpenSeaMap

Updated 2023-11-09 !

The AIS posts on this blog have been very popular so this post will be a follow up which will enable You to show AIS targets, including AtoN:s, on OpenSeaMap, (OSM), together with buoys and beacons.

The application showing the map is SignalK, (SK) a OpenSource project for marine use. 

With the "ais-forwarder" plugin you could send/dispatch the NMEA AIS data to Marinetraffic or Vesselfinder. Another AIS-dispatcher.

The best AIS application ? is found here !

Install
Starting fresh with a Raspberry Pi OS ? You just have to install the Raspberry Pi OS Lite version, no GUI, or other software packages, since SK has its own WEB-server.

Install the server software, Signal K, using these instructions and after that continue below.

Connecting AIS receiver
Now You can add the USB AIS receiver or any other AIS source.

Center Vessel via file
In FSK You can "Center Vessel" in the Map. (Click on the square symbol to the left.) If You don't have a GPS connected its pretty easy to create a fake position with a NMEA 0183 GLL sentence.

A raw GLL, without checksum, could be, (In this case the beacon at Kronborg Castle, Denmark) 

GPGLL,5602.358,N,1237.341,E,000000,A,M

Change to Your Latitude/Longitude and copy the sentence to the input field at this WEB-site

https://nmeachecksum.eqth.net

Which will create an output of

$GPGLL,5602.358,N,1237.341,E,000000,A,M*75

Create a file with 

cd ~/.signalk && nano position.log

and paste the GLL sentence, exit and save.

SK Data Connections
In the SK admin GUI go to ”Server => Data Connections”  and add 

• Input type: File Stream
• Enabled: Yes
• ID: Position
• Data Type: NMEA 0183
• File Name: position.log

Click on "Apply" and then "Restart", in the upper right corner, and check Your position in FSK.

Center Vessel via Node-Red
Another way, low CPU load, is using the Node-Red plugin. Import, to NR, the flow below and it will send the position and true course over ground once a minute.

[{"id":"fd361496.69e0b8","type":"change","z":"d9a5f13f.6387f","name":"Set navigation/position/","rules":[{"t":"set","p":"payload","pt":"msg","to":"{\"longitude\":12.622315,\"latitude\":56.03929}","tot":"json"},{"t":"set","p":"topic","pt":"msg","to":"navigation.position","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":330,"y":40,"wires":[["45f769a.37bfb18"]]},{"id":"45f769a.37bfb18","type":"signalk-send-pathvalue","z":"d9a5f13f.6387f","name":"","source":"","x":590,"y":40,"wires":[]},{"id":"4c2f5356.3f5af4","type":"inject","z":"d9a5f13f.6387f","name":"","topic":"","payload":"","payloadType":"date","repeat":"60","crontab":"","once":true,"onceDelay":0.1,"x":110,"y":40,"wires":[["fd361496.69e0b8","976e0876.f8084"]]},{"id":"976e0876.f8084","type":"change","z":"d9a5f13f.6387f","name":"Set navigation/courseOverGroundTrue","rules":[{"t":"set","p":"payload","pt":"msg","to":"0","tot":"num"},{"t":"set","p":"topic","pt":"msg","to":"navigation.courseOverGroundTrue","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":370,"y":100,"wires":[["45f769a.37bfb18"]]}]

If You don't wan't North up in the map, You can just adjust the course and click on "Show Heading Up" Please note that the course is in radians.

Dispatcher

Install

As said above the  "ais-forwarder" plugin will forward VDM/VDO messages. Install and check the dokumentation.

Test

To test the dispatcher function you could set up a connection type "File Stream" with the sample file for NMEA 2000. Since the ship tracking sites just accepts NMEA 0183 you also have to install the "signalk-n2kais-to-nmea0183" plugin. Set "NMEA 0183 Out Events" to "nmea0183ais".

Setup the forwarder as picture and at a command line check with 

nc -ul 5556