MLAT Flights not shown

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nolatron
Posts: 7
Joined: Tue Jul 28, 2015 2:48 pm

MLAT Flights not shown

Post by nolatron » Mon Aug 03, 2015 11:20 pm

Yesterday I noticed my PiWare dump1090 map is now showing MLAT flights. However, Virtual Radar is not plotting them.

Is VRS capable of showing the MLAT flights on the map as well? They appear in the aicraft list, just not on the map. Been poking around the forums but haven't found a clear answer.

Thanks!
Shaun

agw
Posts: 2241
Joined: Fri Feb 17, 2012 3:20 am

Re: MLAT Flights not shown

Post by agw » Wed Aug 05, 2015 12:36 am

I think PiWare is using Oliver Jowett's MLAT client (https://github.com/mutability/mlat-client). If you have the extended BaseStation output switched on in the client then that will emit BaseStation messages for the MLAT positions that the current version of VRS cannot decode. You will not see MLAT positions on that feed.

That's been addressed for the next version, you will be able to use the extended BaseStation format with VRS. Until then you can either switch extended BaseStation format off in the PiWare client or you can use an AVR/Beast format feed from PiWare instead of the BaseStation one.

If you are merging the PiWare feed with another feed in VRS, and the MLAT aircraft are not showing positions in the merged feed but they are showing positions in the receiver's feed, then that will be because MLAT feeds don't tend to send as many messages for MLAT calculated positions as aircraft usually send so the non-MLAT receiver will keep being nominated by the feed merger as the receiver for all of the aircraft's messages and you'll never (or hardly ever) see the MLAT positions.

That's being addressed in the next version. The current preview version of VRS (http://www.virtualradarserver.co.uk/Preview.aspx) goes some way to addressing it, when you declare the receiver you can say whether it's an MLAT feed and whether it's just positions or whether it's positions injected into a normal feed. In your case go with the positions injected option.

Me109
Posts: 37
Joined: Sat Nov 01, 2014 4:54 pm
Location: KORH

Re: MLAT Flights not shown

Post by Me109 » Sat Aug 15, 2015 7:21 pm

FWIW, I learned that MLAT forwarding is not enabled by default on dump1090-mutability (if that's what you're running).

Once I enabled it (--forward-MLAT), the MLAT comes over dump1090 via the same port as the AVR/Beast data (30005), and is displayed in VRS using the preview version. This works for me, as everything is the same feed into VRS - I have no need to distinguish MLAT/Mode-S contacts from ADS-B - but might not be ideal for all.

nolatron
Posts: 7
Joined: Tue Jul 28, 2015 2:48 pm

Re: MLAT Flights not shown

Post by nolatron » Sat Aug 15, 2015 10:52 pm

I'm using the piaware version right now of dump1090. I've got the preview version no but no MLAT plans show up. So I'm thinking I gotta figure out how to add the MLAT enabler on dump1090 feed.

nolatron
Posts: 7
Joined: Tue Jul 28, 2015 2:48 pm

Re: MLAT Flights not shown

Post by nolatron » Sat Aug 15, 2015 11:55 pm

Got it working with this command with PiAware:

sudo piaware-config -mlatResultsFormat "beast,connect,localhost:30004 basestation,listen,31003"

With the latest preview I think setup a 2nd receiver for 31003 and merged them, setting this receiver as MLAT. So far so good.

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