FlightAware MLAT restrictions

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ProHill
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FlightAware MLAT restrictions

Post by ProHill » Wed Aug 17, 2016 9:13 pm

Heads up on some changes to FlightAware's treatment of MLAT:
http://discussions.flightaware.com/ads- ... 37741.html

To net it out, they are asking users to limit their use of the FlightAware MLAT results to themselves, with no redistribution.

This has obvious implications for anyone who has a public-facing VRS instance. I'm trying to sort out how to meet the requirements without disabling public access to VRS altogether, but I'm not sure it's possible as of now.

It would be good if access to certain feeds could be restricted to authenticated users, but that would also require that authentication be optional. The only other thing I can think of is to set up a second instance of VRS to be public facing, then rebroadcast only non-MLAT feeds to it.

Andy

dsfh2992
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Re: FlightAware MLAT restrictions

Post by dsfh2992 » Thu Aug 18, 2016 4:15 am

Whatever laws will (or won't) be enacted, this move will not alter that process. Even if the US enacts legislation, In today's age of the Internet, servers can be anywhere and I doubt they'll get international agreement on this. By 2020, everything in the US will be ADSB anyhow.

As far as changing their policy of MLAT redistribution, I don't blame them.

ADSBexchange.com will soon offer an _unfiltered_ MLAT service for those who want it.

agw
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Re: FlightAware MLAT restrictions

Post by agw » Tue Aug 23, 2016 1:15 am

If FlightAware are marking MLAT generated messages by sending a timestamp of FF 00 4D 4C 41 54 in Beast format or a message type of MLAT in BaseStation format (which they might be if their code is based off mutability's MLAT client/server) then VRS can detect them and I could potentially add an option to suppress positions, altitudes, speeds & headings that have come from an MLAT message to Internet clients.

However, if FlightAware's MLAT messages are indistinguishable from normal messages then there's no much that can be done.

Regarding showing different feeds to authenticated users... the tricky bit there is having a desktop page that sends the basic authentication challenge to the browser when the user wants to log in but doesn't send it otherwise. I'll have a think about it.

I've added both items to the list.

drencken
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Re: FlightAware MLAT restrictions

Post by drencken » Sat Aug 27, 2016 2:04 pm

Hi,

I'm seeing VRS now showing ICAO codes that start with the ~ character. Is this the result of the obfuscated codes that FA is now sending?

agw
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Re: FlightAware MLAT restrictions

Post by agw » Mon Aug 29, 2016 10:10 pm

No, the ICAO code is a six digit hex number and ~ isn't a hex digit. I don't know where that would be coming from. If it's appearing on a cooked feed then VRS wouldn't be able to parse it into a number so it shouldn't get as far as tracking it. Whereabouts are you seeing the tilde?

drencken
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Re: FlightAware MLAT restrictions

Post by drencken » Tue Aug 30, 2016 12:36 pm

The tilde shows up in the ICAO column in Reports for example. So it seems to save this in the database.

agw
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Re: FlightAware MLAT restrictions

Post by agw » Thu Sep 01, 2016 1:06 am

I think the database writer listens to the BaseStation format feed that gets produced internally for all receivers, a tilde in the ICAO field might make its way to the database that way. I don't think the aircraft would show up in the tracking list though, the aircraft list starts by trying to parse the ICAO into a number and that wouldn't work.

What format is the feed in?

mgunther
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Re: FlightAware MLAT restrictions

Post by mgunther » Sat Sep 03, 2016 7:26 pm

I saw an ICAO with a tilde in front of it in FA Dump1090 today. This was on PiAware image 3.0.4 and one of those flights that are now anonymized by the FA MLAT client.

ProHill
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Re: FlightAware MLAT restrictions

Post by ProHill » Tue Sep 06, 2016 9:51 pm

Yes, these are the anonymized ICAOs that FlightAware is masking based on its block lists. See obj's post here for the details: http://discussions.flightaware.com/post ... ml#p197193

These are indeed making it into my database (including first/last position and altitude), although they do not appear to show up in AircraftList.json, so the track log is not being populated.

Andrew, I'm not sure if it would be desirable or even possible to somehow handle these differently...what do you think?

Andy

Skibox
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Re: FlightAware MLAT restrictions

Post by Skibox » Wed Sep 07, 2016 12:50 am

An option to block them completely would be nice.

/M

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