Hello Everyone,
I have a question, I am Running 1 Flightfeeder version 10 at my Home, but some local aircrafts (they dont have adsb transponder) not showing their location on map, i know MLAT can track them, but here only 3 nearby recievers
according to flightaware we need 4 nearby recievers to complete MLAT operations.
So my question is if i install 2nd flightfeeder / piaware at my home , will it work to complete MLAT operations?
Without knowing the specifics of how the database works, I’m going to guess it’s a “no.” I assume the 4th location is a “check” on the first three, the same way GPS requires 4 satellites to give a position. It would show that the stations are properly synched-up, or not, confirming or rejecting the positional data. FlightAware staff would have to corroborate that, though.
Two MLAT receivers at your one location aren’t going to give better location accuracy. They’re just going to report the same data from the same position with the same time code. The points need to be separate to better triangulate (or “quadrangulate,” if you will) the position. If your job is, let’s say, three to five miles from your home and your boss will allow you to hook up another receiver there, that would give the database what it needs.
Be sure that TIS-B is enabled on your feeder. If you decide to setup another receiver, try one set to UAT frequency (978 MHz ) and enable TIS-B. You should be able to pick up more aircraft, including the GA ones with no ADS-B on board.
Works for me. Good luck!
This is a simplification, but it’s essentially correct.
Multilateration requires solving a system of equations with 4 unknowns (x/y/z position, time of transmission) in much the same way that a GPS receiver solves for 4 unknowns. So you need at least 4 measurements from the same transmission to provide a unique solution. If you have more than 4 measurements, you can use that to refine the solution to deal with measurement noise.
One of those measurements can be the aircraft altitude, if it’s transmitting that, but that’s not always present. The other measurements are message arrival timing data from different receivers.
The quality of the solution depends quite a lot on the arrangement of the receivers around the aircraft (this is analogous to the dilution-of-precision / GDOP value you may see on some GPS receivers)
We require a certain level of quality in the solution before producing results, and that generally means >= 4 receivers with good geometry seeing the aircraft consistently, even when altitude is available. So it’s not quite as simple as “you need 4 receivers”.
If you have an additional location that is at least 3-4km distant from existing receivers, and ideally surrounding the aircraft that you’re interested in, a new receiver there could help with MLAT. Receivers that are closer together than that, don’t really contribute to the mlat geometry.
ok…
Thanks ! 
