Atmospheric ducting helps better tracking?


Placing the antenna on the top most position to see the radio horizon is the best known way to track more flights. Is this also backed by a phenomena called atmospheric ducting??If this works then flights more than 400km away can be tracked easily with our antenna and feeders.

I spawned a stingray!?!

Occasionally? Yes.
Easily? No.


The ADS-B decoding software has some idiot checking in it to prune out undetected multi-bit errors. One of the checks the code makes is a distance check. I think it’s set at around 350km? Configurable if you know where to look. A couple of years ago as parts of this were still being developed, I remember seeing reports on my screen of a commercial aircraft a few thousand km away doing 250 or 300 knots at an altitude of something like 26 feet. Would have been one hell of a ride, but I suspected bit flips instead.

As a ham radio operator, I’ve worked from the California coast to Hawaii on 6 and 2 meters (54 and 144 MHz) SSB. Ducted signals sound weird!

ADS-B packets are pretty short; not sure if ducting would alter them significantly.

bob k6rtm


So it is a kind of phenomena that accidentally happens,we can’t do anything technically to use it on daily basis.


Tropospheric Ducting


wow…many thanks for sharing.


I get some reflections (probably not ducting as such) which I think are from other high altitude aircraft?
I am blocked by hills right behind me to the south, but occasionally get some long range signals (the red rings are 50 miles and the blue are 100 miles, so the outermost ring is 300 miles)


Excellent …but where from you have got this radar clutter layer over range circles??Is this available in virtual radar server??


Yes, I’m using VRS on my internal network on a separate Windows machine .
I set the map receiver range opacity a little light so you can still see the map beneath, the default is too dark for my liking.


I guess this phenomena happened today with my receiver. My antenna height isn’t much,maybe 12ft from ground.I set it up temporarily for severe rain.But today from this height it detected a signal from a distance of 400+ km.Amazing !!


An interesting example of the work Flightfeeder on a flat plain near the sea.
Standard cable is cut off. Cable length is now about 2 meters.