[NEW] Feeding FLARM data to OpenSky

Dear members,

As you know, our main goal is to collect ADS-B and Mode-S data for research purposes. On top of that we are now collecting FLARM messages. For this purpose we use the existing receiver software of the OGN Project. If you already have an OGN receiver setup, then it is really easy to share your FLARM data with us. If not, then you would need to setup an OGN receiver first, as explained here.

If you are willing to share your data with us, FLARM aircrafts received by your station will appear on the OpenSky Explorer and we will store the (raw) messages that your station receives and they will be available to our research community in our Historical Database. Furthermore we are working on a “collaborative decoding” functionality that should enable us to reconstruct messages with a poor SNR that have been received by multiple sensors: this could be especially helpful to track down devices that disappear in areas that are at the edge of the usual coverage.

Feeding with us with your existing OGN receiver is really easy, it is enough to add this line to the OGN .conf file and restart the service.

Demodulator:
{ MergeServer = "flarm-collector.opensky-network.org:20002"; } ;

If you are using a “Ready to use” Image by Sébastien Chaumontet, you just need to change the OGN-receiver.conf file in your /boot partition as follows:

ReceiverName="MyReceiverName\";}; Demodulator:{ MergeServer = \"flarm-collector.opensky-network.org:20002"

Unfortunately it is not yet possible to get detailed data about the sensor, feeding, etc.

Don’t hesitate to contact me if you have any questions. Thank you in advance for your help!

Giorgio

Updated 04.05.2022

unabbreviated link (for easy copy & paste):

Is it possible to check if the feeder is working? Ideally without any FLARM aircraft/glider in sight?

Thx

Hi,

at the moment there is no way for you to see if you are seeding correctly as we are still in a beta stage. However, feel free to hit me up and I will be able to check manually.

Best,

G

Thanks. I am using a Pi Zero W and the image of Sébastien Chaumontet (could not get OGN to work with Raspbian Stretch Lite and manual install)

My local raspi status page (8081) states
Demodulator.MergerServer flarm-collector.opensky-network.org:20002
and my DNS server shows requests for flarm-collector.opensky-network.org . Looks fine and I can see a FLARM data from a REGA helicopter near me on the live map.

I would like to feed OGN data as well, but there is a problem to solve.
I am running a local "Virtual Radar Server" to visualize AC from ADS-B data.
VRS is getting data
- from dump1090-fa ( ADS-B )
- from PilotAware-OGN
PW-OGN converts AC positions from ogn-decode into BaseStation messages.
And here is the problem:
With MergeServer enabled, ogn-decode 0.2.6 frequently crashes, while
ogn-decode 0.2.7 (your version) is running stable, but PW-OGN is reporting
AC positions several thousand km off.

Any idea how to solve this? I am not sticking to PW-OGN is there is another program
converting ogn-decode supplied positions to a format VRS can handle.

Hi,

It is known that the merge server option does not work very well on 0.2.6. I believe that 0.2.7 has a slightly different "text" output format () than the previous version. I assume that the parser that Pilot Aware uses to get the data from OGN-decode does not interpret the data correctly.

I will try to bring up the issue on the Pilot Aware forum.

Best,

Hi,

did you have a chance to address this issue to the PilotAware developers?
Or do you know of another program converting FLARM messages from ogn-decode to e.g. Beast format?
Thank you

Hi,

not yet. Sorry about that. I have no knowledge of other softwares doing the same. It has now been a while since the last OGN software release, I think that it makes sense to expect a new version soon. it might be worth waiting before starting any effort, to see what changes they will introduce.

Best,

Is the data format documented that is used to send the AC positions and time to the MergeServer?

I have upgraded my station to rtl-sdr.ogn 0.2.8 and enabled the merge server.
Observation:
AC seen on my local display oftenly do not show on opensky explorer map.
Are you loosing packets?

Hi,

thanks a lot for your question! We did not receive the new software in advance, so we haven't had the opportunity to check yet. We will do so during the coming weeks and make the necessary adjustments.

What is known is that OpenSky needs more than just one message in order to show an aircraft on the map (although all messages are logged and available in our dataset). If the ogn receiver only gets 1-2 messages the aircraft will not be displayed.

Best,

Giorgio

Is there a particular reason to update ogn-decode? I am using Pawel's latest OGN libs 0.2.9 so not sure what to do, I don't want to change my running OGN feeder ...

I am actually running Pawel´s 0.2.9-ARM binaries since they became available, (and) feeding OpenSky.

So no reason to replace Pawel's ogn-decode? Only the following?

Add the following code to the config file “.conf"

Demodulator:
{ MergeServer = "flarm-collector.opensky-network.org:20002"; } ;

Exactly.

Alright, will try.

Done, that was really easy - first FLARM traffic already received.

How many OGN stations are feeding OpenSky?

The original post was outdated and I have now updated it. There are around 15 OGN stations (mainly in Switzerland) feeding to OpenSky. We would like to improve some details in the backend and the UI before we advertise more this possibility. We are also trying to establish a collaboration with the OGN. Unfortunately, as in most "hobby" projects, time is a scarce resource.

Now 28, nice to see the progress even if it is slow!