FlightAware Discussions

What would cause this graph discrepancy

Hopefully, a couple of images will appear here. First one of the ADS B message rate off a N2 / airspy system"

Second from a XU4 / prostick system:

Both systems same location etc. Obvious question the airspy pic not showing any messages recording and the Prostick pic is showing message recordings. Both systems though working and the airspy far in front of the Prostick result wise.

Are there airplanes displayed in dump1090-fa?

That’s where the graphs get their statistics.

Yes on all maps the tar1090 and also virtual radar.

That screenshot doesn’t even shot “no messages recording”

Or do you mean messages > -3 dB?
Please be more specific -.-

That’s just because dump1090-fa doesn’t gather that statistic when the messages aren’t directly demodulated by dump1090-fa but rather fed from another program.

The data difference in both is "Messages > -3dbfs’. Both units are running individually, not relying on any other feeds. Some more images for the current last hour including adsb tracks seen.

Airspy
Imgur
Imgur

Prostick
Imgur
Imgur

dump1090-fa is not using the receiver but getting messages from airspy_adsb.

So i’ll repeat:
dump1090-fa doesn’t gather that statistic when the messages aren’t directly demodulated by dump1090-fa but rather fed from another program.

Right… if so, then there shouldn’t be any data showing for the airspy unit in adsb message rate, yet the airspy graph still shows messages received, min max, seven day average and positions. Just not showing messages > -3dbs???

When viewing the graph, you would assume there isn’t any messages, 0.0%, > -3dbs on the airspy feed, which is fine. I don;t know what that would mean, may be that is the question, if everything is working, why arn’t there any messages on the airspy unit > -3.dbs??

Other statistics are still gathered.

Right, thank you for that