Survey of measurements of attenuation by rain and other hydrometeors

This paper surveys the most recently reported attenuation measurements at microwave and millimetric frequencies on terrestrial and satellite (slant) radio paths. Greatest attention is given to direct measurements of attenuation, but radar and radiometric techniques are also considered. Measurements relating fading to the various meteorological parameters are reviewed as well as those presenting statistical information for the system designer. From the summary of all available statistical measurements of greater than one year duration, the variation of fade depth (exceeded for 0.01% of the time) with path length is characterised for 11 and 18 GHz on terrestrial paths. The accuracy of radar and radiometric measurements on satellite paths is also discussed, and related where possible to direct measurements with satellite beacons.