Weissberger's model
Weissberger’s modified exponential decay model, or simply, Weissberger’s model, is a radio wave propagation model that estimates the path loss due to the presence of one or more trees in a point-to-point telecommunication link. This model belongs to the category Foliage or Vegetation models.
Applicable to/under conditions[]
- This model is applicable to the cases of line of sight propagation. Example is microwave transmission.
- This model is only applicable when there is an obstruction made by some foliage in the link. i.e. In between the transmitter and receiver.
- This model is ideal for application in the situation where the LOS path is blocked by dense, dry and leafy trees.
Coverage[]
Frequency: 230 MHz to 95 GHz[1]
Depth of foliage: up to 400 m
History[]
Formulated in 1982, this model is a development of the ITU Model for Exponential Decay (MED).
Mathematical formulation[]
Weissberger’s model is formally expressed as
where,
L = The loss due to foliage. Unit: decibels (dB)
f = The transmission frequency. Unit: gigahertz (GHz)
d = The depth of foliage along the path. Unit: meters (m)
Points to note[]
- The equation is scaled for frequency specified in GHz range.
- Depth of foliage must be specified in meters (m).
Limitations[]
- This model is significant for frequency range 230 MHz to 95 GHz only, as pointed out by Blaunstein.
- This model does not define the operation if the depth of vegetation is more than 400 m.
- This model predicts the loss due to foliage. The path loss must be calculated with inclusion of the free space loss.[2]
See also[]
- Fresnel zone
- Radio propagation model
References[]
Further reading[]
- Introduction to RF Propagation, John S. Seybold, 2005, John Wiley and Sons.
- Radio Propagation in Cellular Networks, N. Blaunstein, 2000, Artech House
- The Mobile Radio Propagation Channel, J. D. Parsons, 2000, Wiley
- Mark A. Weissberger (1982). "An initial critical summary of models for predicting the attenuation of radio waves by trees" (PDF). Retrieved 2012-02-01. Cite journal requires
|journal=
(help)
Categories:
- Radio frequency propagation model