5. AIS

AIS stands for Automatic Identification System and is a technology similar to ADS-B, but used for ships. If you follow the steps in this chapter of the tutorial you will be able to receive AIS data and feed it to the big map.

Hardware preparation

You need to change the id / serial number of the SDR stick you want to use for AIS, to distinguish it reliably from other rtl-sdr sticks. You do not want to mix it up after a reboot, it will result in not working AIS.

Plug your AIS stick in a PC with no other RTL-SDR dongle connected. This can be your Raspberry Pi or every other linux computer with the rtl-sdr library installed.

Set the new serial with

sudo rtl_eeprom -s 20000001

You need to reconnect your stick or reboot your system sto access your stick with the new serial number 20000001. Beware that smaller numbers like 2 do not work.

Software installation

If you didn't already, add our package repository first, as shown in the Install Chapter

Install AIScatcher

sudo apt install ais-catcher

test AIScatcher

$ AIS-catcher -d 20000001
Device selected: Realtek, RTL2838UHIDIR, SN: 20000001
Found Rafael Micro R820T tuner
[R82XX] PLL not locked!
Allocating 15 zero-copy buffers
!AIVDM,1,1,,A,339L0eU0010fOHbO76Cp;1ti0000,0*3B ( MSG: 3, REPEAT: 0, MMSI: 211222710)
!AIVDM,1,1,,A,139fw`P001PfOjNO7:mtur4j0<1I,0*26 ( MSG: 1, REPEAT: 0, MMSI: 211533730)
!AIVDM,1,1,,A,13=r2R000:PfKVlO6rw443Dh0<<C,0*56 ( MSG: 1, REPEAT: 0, MMSI: 215909000)

!AIVDM indicates, that you are getting real messages from at least one ship

Adjust config file

Copy the config file template to the right place

sudo cp /etc/ais-catcher.d/rtlsdr.conf.example /etc/ais-catcher.d/20000001.conf

Fill in the credentials for your station with

sudo nano /etc/ais-catcher.d/20000001.conf

[...]
	"http": [{
		"active": true,
		"url": "https://ais.feed.sdrmap.org/",
		"userpwd": "YOURSTATION:THEPASSWORDWESENTYOU",
		"interval": 1,
		"gzip": true,
		"response": false
	},
[...]

Register AIS-catcher as a service

To make AIS-catcher start with your station, we register it as a systemd service like this

sudo systemctl start ais-catcher@20000001.service
sudo systemctl enable ais-catcher@20000001.service

Thats it!