FlightAware Discussions

Graphs1090 Anomaly

ADS-B tracks spike whenever I change gain and restart dump1090-fa. I reduced gain from 49.6 to 46.6. Percent of strong messages went from 3.3% to 2.3%. Is this hardware related or simply a statistical quirk?

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Statistical quirk; when you restart dump1090, it does not preserve information about currently tracked aircraft. So all the currently-visible aircraft are counted as “new” after the restart, producing the spike.

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I know there’s an option within the graphs configuration to set a maximum value which helps but I removed that when we had the tropo opening last week because that graph was pegged fully green.

This can be frustrating though.

I wonder of there’s any way for the graphs to do a ‘sanity check’ on the data and if it suddenly shots up massively for a few seconds and then drops down, then that spike is ignored?

I’m speculating, this may not be possible/practical.

Once hacked my dump1090-fa not to emit any stats.json for the first minute.

That fixes it as the first number after the counter decreases doesn’t count.
I suppose you could stop collectd, restart dump1090-fa, wait 2 minutes and then restart collectd.

Since about 10/30/2019 graphs1090 has not been showing any 978UAT traffic. 978UAT shows up in tar1090. What can I do to remedy this? Thanks!

Probably the switch from skyview to skyaware naming.
Have you tried reinstalling graphs1090?