ADS-B signal dampening with inside antenna


#1

I wonder if it would be worth the effort to install a Pi based flight feeder with antenna inside the top of a church tower? The tower is made out of wood and is covered with thin, almost vertical slates, mains voltage and internet connectivity are also available. Looking out of one of the small windows, one can see an unobstructed stunning view but I have no idea about the signal loss at 1090MHz due to the wood and slates…


#2

MIt should work.
I have two setups that are indoors and see out over 100nm. I am very close to sea level which affects their range.
The view to the horizon is what matters most.

It may be worth testing with an existing setup beforehand.


#3

Go for it and see what you get, sounds like a great site! People often report using antennas inside their roof spaces.


#4

If the roof slates are non-conductive, then they will not attenuate the signal significantly (when dry).
It’s not as good as open air, because of the existing moisture in the wood beams and boards (slates are laid on wood boards), but is workable.

PS: A good test: if you have cellphone service in that place, then most likely it will work for ADS-B too.


#5

Wood and wall material vary a lot. Something like 20-70% reduction depending on the wall so it is very hard to tell until you set one up.

The bigger problem is usually the trees and/or multiple walls.


#6

1 - Attenuation of RF Signal by Glass, Masonry, Wood & Concrete

2 - RF Signal Loss in Penetrating a Building


#7

abcd567, that’s great digging. It confirms what I empirically knew:

  • drywall panels - 0.2…0.4 dB attenuation
  • glass -1…3 dB attenuation (I bet that thermal treated glass is worse due to metal deposit)
  • lumber panels - 3…6 dB attenuation
  • masonry blocks - 20…30 dB attenuation
  • concrete walls - 20-35 dB attenuation