A couple of weeks ago FlightAware announced that version 2.1 of its PiAware software supports live multilateration (MLAT). As the news release stated, “by triangulating the Mode S signal from non-ADS-B aircraft, PiAware can now track twice as many aircraft around the world!” While this give FlightAware a new resource for tracking flights and displaying the information on its own website, FlightAware went a step further and also sends the mlat data back to the individual PiAware installs around the world.
This is actually a very cool thing, because it means you can now see displayed on your virtual radar software’s map aircraft that previously showed up only in the list of planes. For me, it means I’m able to see the positions of roughly 50 per cent more aircraft (at the time that I write this.)
PiAware can inject all of the mlat aircraft into your dump1090 data stream, and dump1090 will display those aircraft in blue rather than the default grey. You can read all about FlightAware’s support for multilateration on their discussion forums. If you haven’t updated your PiAware feeder software in a while, you might want to now!
More advanced users may want to use something other than dump1090 as their virtual radar viewer. In that case, you create an output stream from dump1090 (see the dump1090 help for info) for your preferred application to use. For instance, I have altered my setup so that dump1090 feeds back to Virtual Radar Server, which then rebroadcasts to ModeSMixer2 so I can see the extra aircraft in BaseStation, Globe-S RTL Edition and ADSBScope. Here’s my new setup:
As you can see, I have two instances of ModeSDeco2 running (one for each receiver) and two instances of ModeSMixer2. This was necessary to ensure that the data I’m sending to other flight tracking sites (like FlightRadar24, RadarBox24 and PlaneFinder.net) does not include the mlat data from FlightAware. These sites calculate their own mlat positions and injecting the data from FlightAware would cause errors to creep into the other sites. Think of it as data pollution.
It’s important to note that this update from FlightAware doesn’t mean you’ll receive data from more aircraft – the total number of aircraft your receiver picks up will be the same. Rather, it means that of that total number of aircraft, more will be displayed on your virtual radar map because their positions are being calculated by FlightAware.