Low flying planes on airports not visible?

FlightAware ADS-B Flight Tracking
1

Hi,

my ADS-B setup is a Raspberrypi 3B+ with bookworm OS and Flightaware installation from this site: PiAware - dump1090 ADS-B integration with FlightAware - FlightAware

hardware: Nooelec NESDR Mini 2+ 0,5 PPM TCXO RTL-SDR & ADS-B
antenna is a self made groundplane spider with 8 soldered radials. The sma cable between anntenna and nooelec SRD stick is 5 m long.

the antenna is at 12 m high over the rooftop and has free sight to the direction of the International Frankfurt Airport but I don’t see any landing or starting aircrafts around the airport ? Straight line distance is only 36 km to EDDF.
I saw another ADSB user where the Piaware web interface showed Frankfurt Airport full of planes taking off and landing. Why don’t I see anything?

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I tried to play a little with the SDR gain value but this parameter is only changeble with the piaware iso installed raspberry image, not with piaware installation on a raspbian os. How can I get the low flying airplanes tracked with my adsb setup ?

regards,
Frank

2

It’s because of the curvature of the earth.
At 36km away the airport runway will be about 100m below the horizon, so you won’t see anything at the airport until it is 100m up, at which point it will start to be visible to you.

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3

You can ofc change the gain in /etc/default/dump1090-fa

But the more likely reason as already mentioned is the aircraft are disappearing below the horizon as they descend.

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4

I have 978 UAT on my PiAware setup. With TIS-B enabled you can “see” aircraft not visible with 1090 ADS-B.

5

978 UAT is not used in Europe

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6

I am 45 km away from EDDF, living directly in the approach on days they are coming in from West.

My visibility stops once the aircraft are over Mainz/Wiesbaden for exactly the reason which was mentioned by @LawrenceHill

There was a receiver mounted on the roof somewhere in Darmstadt, almost 30 meters high. That was the only one i’ve seen covering ground traffic in EDDF. But it’s not live anymore