Several bands between about 10 and 48 GHz shared by FS (e.g. microwave links) and FSS (using satellites in GSO or LEO).
In establishing sharing criteria, e.g. max powers radiated, one needs to know how much attenuation is occurring on the interference slant path between satellite and terrestrial station due to gaseous absorption.
In other words, how much protection is the atmosphere providing the terrestrial station?
This is example of how model in Rec. P.676 can be used in a sharing situation in providing an estimate of the gaseous attenuation on the interfering path.
