An aircraft can be heard without sending a position
Some transponder messages tell a receiver useful things without providing an ADS-B position. Multilateration, or MLAT, can estimate the transmitter's location by comparing when the same transmission reaches several receiving sites. FlightAware describes a network of at least four receivers for its multilateration positioning. The sites must hear overlapping traffic, and geometry matters. [1]
One antenna cannot become a complete MLAT network by installing a cleverer map. A client such as mlat-client contributes timed observations to a coordinating server; it does not independently locate an aircraft from one ordinary receiver. [2]
The clocks are part of the instrument
The useful quantity is a difference in arrival time, not the time a web page refreshed. A network has to handle receiver timing and synchronisation. Making the host's clock agree with an internet time server is good administration, but it is not itself the radio-timing solution described by MLAT systems. Follow the network's receiver and location requirements. [1] [2]
Enter the antenna location and the requested height carefully. Read what height reference the form asks for; elevation above sea level and height above the ground are not interchangeable. After moving the antenna, update the appropriate private receiver settings.
A working ordinary feed and a working MLAT contribution are separate milestones. Confirm them separately on the service's diagnostics.
Four receivers is not a guarantee
Imagine several receivers clustered on the same side of a transmitter. Now imagine them spread around it. Counting receivers alone does not describe the geometry. Nor does it establish that they all received the same message with useful timing.
Use the network's own diagnostics for synchronisation and participation. If few nearby receivers overlap with yours, buying a more powerful computer does not create those missing observations. Better community coverage may matter more than another local optimisation.
The illustration is conceptual. It does not draw an actual fix, claim measured accuracy or suggest that the circles shown are a solver.
Why maps and feeds must label the result
A calculated position should retain its provenance. A returned MLAT contact on your map is not evidence that your receiver obtained that aircraft's broadcast latitude and longitude. Combining the two without a label can mislead range comparisons and contaminate another feed. The readsb data format distinguishes position sources and identifies fields derived from MLAT. [3]
Use a local display for enjoyment and diagnosis, but select an outbound source according to the receiving network's contract. In particular, Skylark's documented forwarder excludes third-party MLAT. Follow Flightradar24's separate warning about MLAT when sharing alongside other services. [4] [5]
Sources and review notes
Documentation reviewed on 19 September 2026. Links lead to the source owners. Versions, account benefits and service terms can change. Hardware installation is not independently bench-tested for this edition.
- FlightAware: multilaterationOperator documentation. Multi-receiver positioning and feeder participation.
- mutability / mlat-clientMaintainer repository. A client for a coordinating MLAT server.
- readsb: JSON output formatsMaintainer specification. Field meanings and units. Mutable development-branch documentation.
- Skylark receiver networkProduct entry point. Technical description checked against docs/FEEDER.md at repository revision 6cfa123f0745ed7f1e29c618ad948f7e2c2cf75a. Public page availability was not verified in this build.
- Flightradar24: share your ADS-B dataOfficial feeding guide. Contributor plan and the explicit multi-network MLAT warning.