If we want to meaure the air sensitivity in a chamber, how to calculate the path loss? And in practice, we do the outdoor range test, shall we use the path loss to calculate propagation distance?
air loss is often neglectet over a wide microwave band, at centimeters wavelenght an atmosphere of 20% O2 +80%N2 at 1013 mBar has a behaviour similar to vacuum.
Different is the effect on millimeter and shorter wavelenghts where H2O, O2 and other resonances dominate the path loss. Complicate models exists. if you want, i can share a rough estimation of path loss vs. freq., water vapour, and zenithal angle.