possible issue with feed? lots of up/down spikes in data


#1

Hello,

I’m still new to this Raspberry Pi/ADS-B feed, and I have a question. I have two Pi feeds here at Flightaware.

One feed, the data rises rapidly during peak times and lowers normally during non-peak hours. The FlightAware “Coverage Distribution” map also has some areas where more messages are received directionally in some areas and not as much in others. To me, this seems like a normal scenario.

flightaware.com/adsb/stats/user/ … tats-30028

The other feed has several high/low spikes throughout the same time period. A 10k - 20k increase or drop of the message rate within an hour. It is almost as if there is some sort of disconnect in the data stream? Additionally, the “Coverage Distribution” map has no one area that I am receiving more messages than other areas. Pretty much a plain omni-directional coverage area. This does not seem like a normal scenario.

flightaware.com/adsb/stats/user/ … tats-33264

Both feeds are set up exactly the same. Raspberry Pi (with PiAware), Flightaware ProStick and ADS-B antenna (DPD Productions). Why would one be so different than the other? I’m sure geography comes into play but it just seems to be extreme on the one receiver.

Any thoughts?


#2

The polar graph shows relative values. One of your sites is located close to an airport and is getting a lot of ground positions. These extra positions are throwing off the color scale so much that everything looks more even that it really is. You can mouse over the zone to see the actual message seen in that sector.

If you want a better color representation of your coverage area you would need to collect and process the data yourself.
There are forum threads on how to do this.