Re: A small proposal
Of course the antenna pattern of 5G sites will be primarily horizontal, as airborne 5G use is not to be expected, their users are on or near the ground.
Radio altimeters will send their signal pointing at the ground, and the receive antenna will be pointed at the ground to receive the reflection. Also radio altimeters will use a narrow band signal, whereas 5G is broadband, so less spectrally intense.
They're not likely to clash unless you briefly fly over a 5G site, even then you'd have a lot of discrimination between the two signals and they are not exactly the same frequency.
Biting the hand that feeds IT
