Measurement and modelling of cloud attenuation at millimetre wavelengths

Results are presented from a 93 GHz radiometer over a one-year period. A cloud attenuation model, which uses measurements from radiosonde profiles, has been used to provide a comparison. The effects of rain, water vapour and oxygen have been removed from the radiometer total attenuation record through the use of GPS observations and meteorological measurements at ground level. Agreement between the radiometer and cloud model is good, indicating that the cloud model is able to give an accurate prediction of attenuation due to liquid water clouds