FlightAware Discussions

Feed VRS from PiAware?

Afternoon all,

Before I got the Pi set up with PiAware, I was testing the dongle and antenna on my PC, with VRS.

I’ve got a feeling it is possible (AFAIR) to use PiAware to feed VRS - tell VRS to use a feed / output from PiAware or simmilar?

  1. Is this possible?
  2. How does one do this?



FlightAware has opened a case on your behalf (case #41968). We will do our best to answer your questions there.



Hi cy80rg,

Yes this works for me. Within Virtual Radar Server, I have added a receiver with the following settings. Note this receives data from dump1090 (in my case, the mutability version) and not from PiAware:

Format: AVR or Beast Raw Feed
Connection Type: Network
Port: 30005

Use the ‘Test Connection’ button to make sure it works.


@mgunther - thansk for that - have just ahd a fiddle myself and came to the same conclusion :slight_smile:

Can you confirm doing this doesnt send the data to the local VRS instead of FA?
(I.e the data will be sent to both).

Had this set up, VRS can connect fine, sees data - but sees zero aircraft after 30 mins… will leave longer if yo can confirm the above.

Interestingly, VRS “statistics” say that:

c89% of messages has no adsb payload
c62 % had “Bad Parity PI”

Is that normal?

OK, those stats I just quoted relate to Mode S - ADSB reports 6,000+ messages recieved, 0% rejected.


Still tracking zero aircraft… seeing as Ive done the same as you in your post, I’ll assume this is ok?


Ok, so just twigged…

My VRS has two recievers listed… one that I added back when I first tested my antenna locally on the PC when I built it, and the network connected Rpi.

Although I’ve reinstalled VRS (to change the port number) and tried to remove the old reciever listing, it remains in the list.

The web ui wastrying to use that one, rather than the network connected RPi…
Just notcied that in settings, switched to the RPi , and all is fine!

Double Doh… :wink:

Oh well, learned something new…

Glad it worked out! dump1090 is not really “sending” data anywhere. It makes it available on different network ports to any program that asks for it, like PiAware, VRS, etc. So you can have different programs “pulling” the data at the same time. That’s my understanding anyway :wink:

Thanks mgunther, these things seem obvious once you “twig”, but trying new things is how we learn - exactky the reason I’ve just got into this…

Thanks for your help mate - got a few more questions re VRS and PiAware (long term logging / archive / distance heat map), but I take it discussing VRS on the FA forum here is a no-no?

These are Mode S messages i.e. not extended squitter; it’s normal to get a lot of them.

c62 % had “Bad Parity PI”

This is a complicated one…

For some message types, SSR will send a query on 1030MHz that includes an interrogator identifier that identifies the particular radar.
The transponder assembles a response, computes the CRC, XORs the low bits of the CRC with the interrogator identifier, and sends the result.
The SSR then XORs its own identifier with the received message to recover the CRC. If the CRC is bad, either the response was damaged,
or it is a response to a different radar’s query - either way the radar can safely ignore it.

This scheme is “PI” - “Parity/Interrogator”

It causes a problem for passive receivers like us, though, because we only see the reply on 1090MHz and don’t see the query on 1030MHz that has the interrogator identifier.
So we don’t know whether an apparently-bad CRC means “this is an undamaged response to a SSR interrogation” or “this is a damaged response to a SSR interrogation” or “this is a damaged spontaneously-generated message”. Those messages are what VRS calls “bad parity PI”. It’s not really bad, it’s more like “it’s non-zero and I don’t know if that’s bad or not”.

So your guess is as good as mine as to whether 62% is normal or not :wink:

I have seen VRS mentioned a few times before here in this forum, so I don’t think there are any rules that say it should not be discussed. But to be honest, I don’t know much about it and have only used it a couple of times to determine the range of my receiver.

@obj - thanks for the detailed info!

Get the general gist, all rather beyond my experience, but interesting none the less :slight_smile:

I am running VRS on a separate Ubuntu server that connects to my Piaware box on port 30003 and it works fine. Does not redirect Piaware output away from FA. They both use the data.