Millimeter-Wave Propagation in Moist Air: Model versus Path Data,
Abstract:
A practical atmospheric millimeter-wave propagation model MPM is updated and tested with experimental data from horizontal, line-of-sight links when there is no precipitation. The MPM computer program predicts attenuation and delay properties of moist air over ranges in frequency from 1 to 1000 GHz and in height from 0 to 30 km. Input variables are radio path distributions of pressure, temperature, relative humidity, and a suspended droplet concentration simulating haze and fog conditions. Terrestrial path data from millimeter-wave propagation experiments, including those from a 27 km link operated at 11.4, 28.8, and 96.1 GHz by the Institute for Telecommunication Sciences ITS, have been analyzed. Calibrated mean signal levels permitted studies of water vapor losses. In addition, a spectral analysis was performed of clear-air scintillations caused by turbulence. In general, good agreement is obtained with the MPM for test frequencies up to 430 GHz. Author