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 an