Add the following to the environment section of the Ultrafeeder service in your docker-compose.yml:

- ULTRAFEEDER_CONFIG=
    adsb,feed.mlat.uk,30004,beast_reduce_plus_out;
    mlat,feed.mlat.uk,31090;
    mlathub,feed.mlat.uk,30104,beast_reduce_out;

Restart the container and Ultrafeeder will forward your anonymous ADS-B data, join the mlat.uk MLAT server, and share the MLAT results it collects from other networks.

Keep a ; between every entry, including any you already have for other networks. Without it, two entries run together and the MLAT client will not start. Before joining MLAT, check your receiver’s position and station name; see the MLAT tab.

Aircraft data

1. Go to your ADSB.im setup page.
2. Open the Settings > Expert tab.
3. Find the field for Ultrafeeder arguments, usually at the top left.
4. Paste the following string and press submit:

adsb,feed.mlat.uk,30004,beast_reduce_plus_out;mlat,feed.mlat.uk,31090;mlathub,feed.mlat.uk,30104,beast_reduce_out;

ADSB.im will now forward your anonymous data to feed.mlat.uk and join the MLAT server. There is no separate client to install. Check that the location and site name on the ADSB.im Basic setup page are accurate, as MLAT relies on them (see the MLAT tab).

Vessel data

If your ADSB.im image includes AIS-Catcher / Shipfeeder integration, you can share vessel data the same way:

1. On the same setup page, find the AIS / Shipfeeder configuration section.
2. In AIS Station Name, enter a name in the format ais-uk-<area code>, for example ais-uk-ne1.
3. In AIS Extra Options, make sure the following is included:

-u feed.mlat.uk 50001

Once saved, one station contributes both aircraft and vessel data to the network.

Shipfeeder (Docker Compose)

Add the following to your docker-compose file:

- UDP_FEEDS=feed.mlat.uk:50001

Command line

-u feed.mlat.uk 50001

AIS-Catcher web interface

1. Log in to your AIS-Catcher web interface.
2. Click Output, then select UDP.
3. Enter the following details:

• Host: feed.mlat.uk
• Port: 50001
• Description: mlat.uk
• Message Format: NMEA

Once saved, AIS-Catcher will forward your vessel data to feed.mlat.uk. Make sure your network allows outbound UDP to port 50001.

Multilateration works out an aircraft’s position from the tiny differences in when several receivers hear the same signal. It needs at least three or four stations that can see the same aircraft, so coverage grows as more people in an area join.

What you need

• An accurate receiver position. Set READSB_LAT, READSB_LON and READSB_ALT (antenna height above sea level, for example READSB_ALT=45m) to within a few metres. A wrong position breaks the timing for everyone nearby, and the server will set that station aside.
• A station name. Set MLAT_USER in the format adsb-uk-<area code>, for example adsb-uk-ne27. It can only contain letters, numbers, - and _.
• Outbound TCP to port 31090 on feed.mlat.uk.

Why does my station show no MLAT peers?

A peer is another station your station can synchronise its clock with, which means one close enough to hear many of the same aircraft, usually within about 100–300 km. If there are none yet, your station stays connected and keeps sending data, but the server has nothing to compare it with, so it cannot work out any positions. Some feeders, including ADSB.im, may then show an MLAT warning. This is normal while you are the first in your area, and it clears as other people nearby join. Your ADS-B data is not affected, and neither is MLAT on other networks you feed. The MLAT peers column on the Feeders tab shows how many peers your station has.

Joining

Add this entry to ULTRAFEEDER_CONFIG, as shown on the Ultrafeeder tab:

mlat,feed.mlat.uk,31090;

Your Ultrafeeder log should show Handshake complete and a welcome message from mlat.uk. MLAT positions then appear on your own tar1090 map as well as on mlat.uk, and your station shows an MLAT badge on the Feeders tab.

Privacy

Your exact position is only used by the server for the timing calculations and is never published. On the Feeders map, MLAT stations are shown somewhere within about 5–10 km of their receiver. To leave out your station name and that approximate position (your feeder is then placed by IP address, as other feeders are), add --privacy to the entry:

mlat,feed.mlat.uk,31090,--privacy;