September 1985 | Journal Article
An Updated Model for Millimeter Wave Propagation in Moist Air
Cite This Publication
Hans J. Liebe, “An Updated Model for Millimeter Wave Propagation in Moist Air,” Radio Science 20, no. 5 (September–October 1985): 1069–1089. https://doi.org/10.1029/RS020i005p01069
Abstract: A practical atmospheric Millimeter-Wave Propagation Model (MPM) is formulated that predicts attenuation. delay, and noise properties of moist air for frequencies up to 1000 GHz. Input variables are height distributions (0–30 km) of pressure, temperature, humidity, and suspended droplet concentration along an anticipated radio path. Spectroscopic data consist of more than 450 parameters describing local O2 and H2O absorption lines complemented by continuum spectra for dry air, water vapor, and hydrosols. For a model (MPM*) limited to frequencies below 300 GHz, the number of spectroscopic parameters can be reduced to less than 200. Recent laboratory measurements by us at 138 GHz of absolute attenuation rates for simulated air with water vapor pressures up to saturation allow the formulation of an improved, though empirical water vapor continuum. Model predictions are compared with selected (2.5–430 GHz) data from both laboratory and field experiments. In general, good agreement is obtained.
Keywords: radio propagation; atmospheric propagation; millimeter-wave propagation model; MPM
For technical information concerning this report, contact:
Ryan S. McCullough
Institute for Telecommunication Sciences
(202) 893-4551
rmccullough@ntia.gov
For funding information concerning this report, click this link.
Funding Information
Performing Agency
Disclaimer:
Certain commercial equipment, components, and software may be identified in this report to specify adequately the technical aspects of the reported results. In no case does such identification imply recommendation or endorsement by the National Telecommunications and Information Administration, nor does it imply that the equipment or software identified is necessarily the best available for the particular application or uses.
For questions or information on this or any other NTIA scientific publication, contact the ITS Publications Office at ITSinfo@ntia.gov or 303-497-3572.