ModeSDeco2 and ModeSMixer2 - console programs for RTLSDR and transcoding

[ktso44615]

I did an additional test... so as I wrote in my previous post: when connecting to the port 30108 (output from ModesMixer2) with VRS, all the airplanes are visualized, so I tried to run a second instance of ModesMixer2, conneting to the same 30108 port... but the MLAT airplanes were missing again. So it's not properly a bug, it's ModesMixer2 not supporting MLAT at all, unfortunately.

Ok, so you are saying that ModesMixer2 isn't having a problem with taking MLAT data in and feeding it back out on another port / in another format -- the problem lies with ModesMixer2 displaying any MLAT results locally in its web interface.  Is that right?

Mike

[arctic]

all the airplanes are visualized

Including MLAT plots?

What do you mean with "plots"? in VRS they are shown like other planes, but the callsign/icao has a "*" next to the name.

Here's an example (I cut the image) the first aircraft has a mode-s transmitter, but the position is sent back by MLAT to me and then feeded to VRS:

[arctic]

I did an additional test... so as I wrote in my previous post: when connecting to the port 30108 (output from ModesMixer2) with VRS, all the airplanes are visualized, so I tried to run a second instance of ModesMixer2, conneting to the same 30108 port... but the MLAT airplanes were missing again. So it's not properly a bug, it's ModesMixer2 not supporting MLAT at all, unfortunately.

Ok, so you are saying that ModesMixer2 isn't having a problem with taking MLAT data in and feeding it back out on another port / in another format -- the problem lies with ModesMixer2 displaying any MLAT results locally in its web interface.  Is that right?

Mike

Exact... they are merged together with the other data and passed to the output port, but the ModesMixer2 is unable to visualize them in its own web interface.
I'm not sure about the difference of a direct ADSB data, and those ones reported back by dump1090-mutability, but both dump1090 web interface and VRS are capable of handling it and visualize the MLAT planes, ModesMixer2 doesn't, maybe it gets confused by the fact that the airplane is read two times: one directly from the ADSB receiver (but without the position) and the other reported back via MLAT (with the position) and it may discard the second packet believing it is a duplicate (I'm just guessing).

[Anmer]

What do you mean with "plots"? in VRS they are shown like other planes, but the callsign/icao has a "*" next to the name.

MLAT positions are "plotted" as opposed to the aircraft position being transmitted in the Mode-S message.  However, I would expect the Mode-S message to include a flight ID (callsign) and ICAO hex code.

[arctic]

What do you mean with "plots"? in VRS they are shown like other planes, but the callsign/icao has a "*" next to the name.

MLAT positions are "plotted" as opposed to the aircraft position being transmitted in the Mode-S message.  However, I would expect the Mode-S message to include a flight ID (callsign) and ICAO hex code.

Do you mean the triangulation... yes I received the mode-s signal, and i transmit my data to the server, if there's 2 or more people on the server, receiving the same airplane and trasmitting MLAT (timecode), the airplane is triangulated and its position is sent back to all of us in beast format (mutability):



...I dunno what how this packet is different than the normal one, but VRS can handle it.. ModesMixer2 doesn't.

[Anmer]

What software are you using to plot the non-ADS-B aircraft and achieve an MLAT position?

[arctic]

What software are you using to plot the non-ADS-B aircraft and achieve an MLAT position?

I believe you mean what "service" ...?

Anyway, as software I use dump1090-mutability to receive the data from my receiver; then I use mlat-client to send (and receive back) the MLAT data to/from the servers, I then use both dump1090 or Virtual Radar Server to visualize the MLAT calculated positions.
At the moment there's two (global / non private) services that are sending back the MLAT calculations taking advantage of the mutuality, but only when you partecipate to the triangulation, one is FlightAware, the other is ADSBEXchange.

[ktso44615]

What do you mean with "plots"? in VRS they are shown like other planes, but the callsign/icao has a "*" next to the name.

MLAT positions are "plotted" as opposed to the aircraft position being transmitted in the Mode-S message.  However, I would expect the Mode-S message to include a flight ID (callsign) and ICAO hex code.

Do you mean the triangulation... yes I received the mode-s signal, and i transmit my data to the server, if there's 2 or more people on the server, receiving the same airplane and trasmitting MLAT (timecode), the airplane is triangulated and its position is sent back to all of us in beast format (mutability):



...I dunno what how this packet is different than the normal one, but VRS can handle it.. ModesMixer2 doesn't.

A few things.

1.   In VRS, the * next to the callsign does not denote MLAT

The * next to the callsign indicates the callsign may not be correct [and was obtained from a lookup of previous data from an external location most likely].

If you want to see what is MLAT, go into the VRS web interface, select Options, then select LIST, click the lock to unlock the structure, and add MLAT and RECEIVER to the list.

That way, you can see what was coming in from MLAT results as well as see what is coming in from each RECEIVER that you have set up.

Of note:   If you are connecting to Dump1090 on piaware (because you are primarily feeding FA) and pull that data into VRS, that data includes both ADSB and MLAT.

I have these receivers in my VRS:

DUMP1090 (from piaware/FA)
AIRSPY
ADSBExchange MLAT

Results i get in specifically from ADSBExchange MLAT are tagged with the "ADSBExchange MLAT" receiver line in the aircraft list
Results I get in specifically from my Airspy (which is only ADSB) are tagged with "AIRSPY" in the receiver line
Results I get in from DUMP1090 (my FA stuff) are tagged as DUMP1090 in the receiver line
* and those BEAST results pulled from DUMP1090 include both the  ADSB I feed to FA as well as the results froM FA

I'm guessing that the reason that the FA ADSB and MLAT results all come in via the BEAST port on Dump1090 is because the FA MLAT results are being fed directly into Dump190 (by the FA scripts) so that the MLAT can be seen on the Dump1090 screen.

That does concern me, because I don't want to send back out [to any other network] MLAT results from FA.  It's not fair.  Nobody else deserves FA's MLAT results.   FA is gracious enough to allow me to have access to the MLAT results and as such I don't want to propogate those results back out to anybody else.

I suspect that anybody feeding to FA using piaware / dump1090, and who grab BEAST data from Dump1090 and inject it into somebody else's plane network, are actually injecting ADSB and MLAT (from FA) into that other network.   And I don't know that there is a way to prevent that.   The "other" networks might claim that they are dropping that MLAT data, but I wouldn't be so sure about that.

Mike


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[Anmer]

I believe you mean what "service" ...?

No I meant what software.

I assume you're not running your own MLAT server?  If not, which remote service are you using?  FlightAware, ADSBExchange or a different one?

[ktso44615]

I believe you mean what "service" ...?

No I meant what software.

I assume you're not running your own MLAT server?  If not, which remote service are you using?  FlightAware, ADSBExchange or a different one?

He is feeding MLAT to FA and ADSBExchange, and he is grabbing the MLAT results of both FA and ADSBExchange and plotting them in VRS.

m

[arctic]

Yes, I mentioned them above (FA and ADSBEx).

I didn't know about the "*", but coincidentally it appears on each MLAT plane because the callsign is merged between the two data (MODE-S and the data returned by MLAT), now I added the MLAT column on VRS, tnx.

I send the MLAT calculation to both dump1090 and ModexMixer2 adding a second --result output to the FA mlat client command line:

--results beast,connect,localhost:30104 --results beast,connect,localhost:30107

30104 is the net-bi-port of dump1090, and 30107 is the --inServer port of ModeSMixer2.

I'm feeding VRS via the output port of ModexMixer2.
Also, I think dump1090 doesn't provide any MLAT output on the 30005 port (bo-port), otherwise the data will be redundant, it only output the data received from the receiver... but I will check this.

[Anmer]

He is feeding MLAT to FA and ADSBExchange, and he is grabbing the MLAT results of both FA and ADSBExchange and plotting them in VRS.

Thanks.  And that appears to work OK, displaying the MLAT traffic in VRS?  But when attempting to forward MLAT using ModeSMixer2, the MLAT traffic doesn't show?  Both from FlightAware and ADSBExchange?

[ktso44615]

He is feeding MLAT to FA and ADSBExchange, and he is grabbing the MLAT results of both FA and ADSBExchange and plotting them in VRS.

Thanks.  And that appears to work OK, displaying the MLAT traffic in VRS?  But when attempting to forward MLAT using ModeSMixer2, the MLAT traffic doesn't show?  Both from FlightAware and ADSBExchange?

If you use ModesMixer2 (at least the version he and I have tried) to grab input MLAT data and forward it elsewhere, the forwarding of the MLAT data works.   BUT, if you view the local web interface of that ModesMixer2 instance, the ModesMixer2 web interface itself does not display any of the MLAT results that are passing through it.   It only displays ADSB.

But, now that I think about it, I think even MLAT results shows up as "ADSB" -- because they do on my VRS.   So I will have to try this again and see if the MM2 web display is truly showing only ADSB or if it is showing ADSB+MLAT under the same "A" icon.

Mike

[arctic]

He is feeding MLAT to FA and ADSBExchange, and he is grabbing the MLAT results of both FA and ADSBExchange and plotting them in VRS.

Thanks.  And that appears to work OK, displaying the MLAT traffic in VRS?  But when attempting to forward MLAT using ModeSMixer2, the MLAT traffic doesn't show?  Both from FlightAware and ADSBExchange?

ModesMixer2 forwards the data correctly (VRS can visualize its output), but it's not capable to visualize the MLAT traffic in its own web map (as dump1090 or VRS can do).

[Anmer]

Thanks to both of you, I understand the problem better.