FlightAware Discussions

Low aircrafts / acft with positions ratio

Hello all,

I’m running a new setup for some days, including a FA Pro Stick Plus and 3ft of RG58 to the antenna, with SMA connectors everywhere.
I’ve seen a boost in the number of messages received, in number of positions as well.
However, it seems to me I have a poor number of aircrafts w/position seen by the receiver. Sometimes, even not 50% of the seen aircraft are reported with positions.

I live near a major airport, therefore I have a lot of airliners with ADS-B transceivers, and IMHO I should have something like 90% of aircrafts with positional info.
Dump1090-fa & piaware are up to date (3.8.0) on Armbian Buster.

Am I missing something here? Is that normal?

Best regards,
Guillaume.

https://github.com/wiedehopf/graphs1090#graphs1090

Might be your gain is set too high.
Thoughts on optimizing gain

Other possibility: Interference, you might need the FA filter in addition to the integrated filter.
RG58 isn’t good cable, but for 3 ft it’s not too bad.

With such a short cable i would assume an indoor antenna?
Depending on the materials of the house around the antenna, results can vary dramatically.
Above the house is always best, if that’s not possible on the side of a house is the 2nd best option for a good 180 degrees of view.
Also depends on other houses nearby of course.
ADS-B is mostly line of sight.

That’s an outdoor antenna, with an outdoor board. The RG58 seemed good enough for me for such a low distance.
However it is just a window-mounted antenna, as the roof is not accessible.
I used to run a more classic SDR before, and had better position ratios.
Gain may not be too high, as I have about 2% of strong messages.

The new --fix --fix option seems to improve things a bit (at the expense of a huge number of tracks & single tracks), I may well go for a filter on the signal path.

Thanks for your thoughts on this!

Do you have a window feed through, if so could you give a link to the specific product?

No specific product, I use a PoE injector (12V) , and an Ethernet flat cable running between the window and its frame. The “box” incoporates the voltage regulator, Orange Pi board, and the SDR. I may post a picture of the internals.

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Much better than trying to put the signal/coax through there!
Just checking for possible issues :wink:

One that came to my mind, is the enclosure is a bit too small, and I’ve had to bend the RG58 “a bit” to fit, perhaps harming it.
I’m looking to get a wider enclosure to optimize placement of the elements and to avoid such caveats.