Millimeter–wave Propagation Model (MPM)
The Millimeter-wave Propagation Model (MPM) calculates the
complex refractivity N for atmospheric conditions. The output is
expressed in real and imaginary parts of N, or in specific rates of
power attenuation and propagation delay.
- Real Part of Refractivity, N' [ppm]
- Imaginary Part of Refractivity, N" [ppm]
- Non-dispersive Refractivity, No [ppm]
- Attenuation, 0.1820 F N" [dB/km]
- Dispersive Delay, 3.3356 N' [ps/km]
- Total Delay, 3.3356 (N' + No) [ps/km]
The input data includes the frequency (F), pressure (P),
temperature (T), relative humidity (RH), and rain rate (RR). For 80
< RH < 99.95%, a haze model predicts water droplet density
(W) for four climate zones (Rural, Urban, Maritime, Maritime+Strong
Wind). The haze growth model is dependent on hygroscopic aerosol
reference density (wA), which is specified at 80% RH. At 100% RH, a
suspended water droplet density is specified to simulate fog or
cloud conditions. Partial vapor pressure, E is calculated from RH
and the saturation vapor pressure, Es(T), over liquid water (for T
> 0 C) or ice (for T < -40 C). In the temperature range -40
<= T <= 0 C, the user specifies Es over liquid water or ice.
This criteria also defines whether water droplets or ice particles
contribute to attenuation and delay.
- Frequency, 1 <= F <= 1000 [GHz]
- Barometric pressure, 0 <= P <= 1100 [mb]
- Temperature, -80 <= T <= 50 [C]
- Relative humidity, 0 <= RH (=100E/Es) <= 100 [%]
- Rain Rate, 0 <= RR <= 200 [mm/hr]
- Water-droplet density, 0 <= W <= 10 [g/m3]
MPM93 is based on Dr. Hans Liebe's final
publication. MPM Software (which operates in a DOS
environment) that aligns with this publication is available in
three different versions, which compute frequency, humidity, and
pressure profiles. It is necessary to include the following
spectroscopic line coefficient data files in the working directory:
oxygen.dat and water.dat.
The MPM software is available for download as a "zip" file.
The download contains software developed by NTIA. NTIA does
not make any warranty of any kind, express, implied or statutory,
including, without limitation, the implied warranty of
merchantability, fitness for a particular purpose, non-infringement
and data accuracy. NTIA does not warrant or make any
representations regarding the use of the software or the results
thereof, including but not limited to the correctness, accuracy,
reliability or usefulness of the software or the results. You can
use, copy, modify, and redistribute the NTIA-developed software
upon your acceptance of these terms and conditions and upon your
express agreement to provide appropriate acknowledgments of NTIA's
ownership of and development of the software by keeping this exact
text present in any copied or derivative works. By clicking this link to download the
software, you acknowledge that you have read the above
ITS publications related to MPM include:
 H.J. Liebe, G.A. Hufford, M.G. Cotton, " Propagation modeling of moist air
and suspended water/ice particles at frequencies below 1000
GHz," Proc. NATO/AGARD Wave Propagation Panel, 52nd meeting,
No. 3/1-10, Mallorca, Spain, 17 - 20 May, 1993. (Download)
 H.J. Liebe, P.W. Rosenkranz, and G.A. Hufford, "Atmospheric
60-GHz oxygen spectrum: New laboratory measurements and line
parameters", Journal of Quantitative Spectroscopy and Radiative
Transfer, vol. 48, no. 5/6, pp. 629-643, 1992.
 H.J. Liebe, G.A. Hufford, T. Manabe, "A model for the
complex permittivity of water at frequencies below 1 THz",
International Journal of Infrared and Millimeter Waves, vol. 12,
no. 7, pp. 659-675, Jul. 1991.
 G.A. Hufford, "A model for the complex permittivity of ice
at frequencies below 1 THz", International Journal of Infrared and
Millimeter Waves, vol. 12, no. 7, pp. 677-680, Jul. 1991.
 H.J. Liebe, G.A. Hufford, and R. DeBolt, "The atmospheric
60-GHz oxygen spectrum: Modeling and laboratory measurements", NTIA
Report 91-272, Mar. 1991.
 H.J. Liebe,"MPM - An atmospheric mm-wave propagation model",
International Journal of Infrared and Millimeter Waves, vol.10,
no.6, pp. 631-650, June 1989.
 G.A. Hufford and H.J. Liebe, "Millimeter-wave propagation in
the mesosphere", NTIA Report 89-249, Sept. 1989.
 H.J. Liebe, T. Manabe, and G.A. Hufford, "Millimeter-wave
attenuation and delay rates due to fog/cloud conditions", IEEE
Transactions on Antennas and Propagation., AP-37, no. 12, pp.
1617-1623, Dec. 1989.
 H.J. Liebe, G.A. Hufford, "Modeling millimeter-wave
propagation effects in the atmosphere, " AGARD, CP-454, Oct.
 H.J. Liebe, "A contribution to modeling atmospheric mm-wave
properties," Frequenz, vol.41, no. 1/2, pp. 31-36, Jan./Feb.
 H.J. Liebe and D.H. Layton, "Millimeter-wave properties of
the atmosphere: Laboratory studies and propagation modeling",
NTIA Report 87-224, Oct. 1987.
 H.J. Liebe, "An updated
model for millimeter-wave propagation in moist air", Radio
Science, vol. 20, no. 5, pp. 1069-1089, May 1985.
For information concerning MPM, contact Michael G.