I started pulling MLAT data from port 30106 and I noticed that some of the ICAO numbers have a “~” (tilde) character in front of them. Is this intentional and if so, what does it indicate?
Non-ICAO addresses (anonymized mlat)
I’ve been seeing a lot more of these recently and not super excited about it.
Maybe check out adsbexchange.com/
I think they are starting a hobbyist oriented (not airliner oriented) MLAT tracking.
I am currently feeding Flightaware, FR24, Planefinder, and adsbexchange.
Last time I checked, around 4% of the aircraft showing in dump1090 were anonymized MLAT. I know originally I had read it would be around 1% but it appears to be quickly climbing.
Showing 7.25% Anonymized MLAT now.
Agreed. I love FA, and I always feed to it first and foremost. But I’ll feed anywhere that’ll give me MLAT results [anonymized or not]. ADSBExchange is a great choice. It’s easy to set up your RPI3 to feed ADSB/MLAT to ADSBExchange, and to get MLAT results returned to you so that you can make use of them - all while your RPI3 is doing it’s normal feeding routine to FA. It [ADSBExchange] does suffer from lack of coverage, but if more people fed to ADSBExchange while feeding to FA, MLAT coverage would increase.
Of course, one must keep in mind that ADSBExchange isn’t an enterprise like FA. The resources of the person who operates it can only goes so far. At some point it will either become overburdened, or people using it will need to donate to keep it going. The person who operates it is a pretty nice guy. I’ve dialoged with him numerous times, and he has always replied.
I’m not sure how to gauge what percentage of MLAT return data on FA is anonymized. But if it’s going up to 7-8%, that certainly doesn’t sound good. Ill still feed to FA no matter what, but I’m hoping / hopeful that the anonymization trend doesn’t steadily increase.
There’s not been any particular change with mlat anonymization; the rates that you see are going to depend a lot on what sort of traffic you see.
Note that if you are merging mlat results from more than one source, you are likely to have jittery tracks for aircraft that are seen by more than one mlat system since they will have different ideas of the exact position.
To segregate Adsbexchange Mlat, please see this post:
After making changes as in above post, add a receiver in VRS for adsbexchange MLAT:
Format: AVR or Beast Raw Feed
Connection Type: Network, Normal
Network: Push Receiver, Port 30102
Sorry for a n00b question - how can you tell the % of anonymous MLAT? I’ve looked over the stat page and it sadly isn’t obvious to me.