The most complete page I can find relating to rain-/fog-attenuation at 2.4 GHz is
"What Effect does Terrain or Water have on Propagation?"
(which says ..

What effect does rain or fog have on performance?

2.4 GHz signals may be attenuated by up to 0.05 dB/km (0.08 dB/mile) by torrential rain (4 inches/hr). Thick fog produces up to 0.02 dB/km (0.03 dB/mile) attenuation. At 5.8 GHz, torrential rain may produce up to 0.5 dB/km (0.8 dB/mile) attenuation, and thick fog up to 0.07 dB/km (0.11 dB/mile). Even though rain itself does not cause major propagation problems, rain will collect on the leaves of trees and will produce attenuation until it evaporates.

.. but it's not supported with references)

This is where I originally found the figure of 0.02 dB/km in rain at 150mm/hour (but it's not supported with references either)

www.alvarion-usa.com/RunTime/Materials/KnowledgePoolFiles/ C3_Radio_Signal_Propagation.pdf

Here are some more LOS propagation-related URLs (some or all of which you may already have)


Searches keep revealing more documents. I'll try to gather a useful subset.

More soon

John :)

(: John Waters :)
john@greybox.uklinux.net | john@grey-box.demon.co.uk
0845 458 0626 | 01686 413639