How do I interpret Aircraft-values in "/tmp/piaware.out"?

FlightAware ADS-B Flight Tracking
1

I am setting up my own statistics for PiAware with Munin and I’m a little bit confused about the numbers in the PiAware-logfile.


>cat /tmp/piaware.out.yesterday | grep "Aircraft:"
01/02/2016 11:08:44 mlat(32156): Aircraft: 10 of 17 Mode S, 21 of 50 ADS-B used  
01/02/2016 11:23:44 mlat(32156): Aircraft: 5 of 15 Mode S, 17 of 40 ADS-B used  
01/02/2016 11:38:44 mlat(32156): Aircraft: 11 of 18 Mode S, 20 of 46 ADS-B used  
01/02/2016 11:53:44 mlat(32156): Aircraft: 13 of 20 Mode S, 21 of 39 ADS-B used  
01/02/2016 12:08:44 mlat(32156): Aircraft: 8 of 17 Mode S, 21 of 48 ADS-B used  
01/02/2016 12:23:45 mlat(32156): Aircraft: 15 of 25 Mode S, 20 of 56 ADS-B used  
01/02/2016 12:38:45 mlat(32156): Aircraft: 11 of 20 Mode S, 19 of 56 ADS-B used

Let’s take “Aircraft: 10 of 17 Mode S, 21 of 50 ADS-B used” as an example, what do these numbers mean? How many aircrafts did I “see”? 50? 67? What do 10 and 21 mean and what 17 and 50?

Thanks for help!

PS: Bonus karma for a way to get this data every 5 minutes, not 15. Is there a way?

2

These are specifically multilateration stats. They are instantaneous snapshots of the number of visible aircraft, and how many of those are actually in use for multilateration (i.e. are forwarding data to the mlat server). Mode S and ADS-B are nonoverlapping categories of aircraft (it means “Mode S without ADS-B” when it says “Mode S”).

Source code is here: github.com/mutability/mlat-clie … or.py#L207

There’s no simple way to change the interval, as the piaware package ships a frozen (cxfreeze) copy of mlat-client.

3

Thanks for the answer. So in the example “Aircraft: 10 of 17 Mode S, 21 of 50 ADS-B used” I see a total of 67 aircrafts and 31 are in use for multilateration?

4

Yes.

5

BTW obj, this is the result:

http://i.imgur.com/xZAXzIy.png

6

Nice!

Just for clarity, the ADS-B aircraft are only used for synchronization, they’re not actually multilaterated at all.