A Novel Ground-Based Microwave Radiometer for High Precision Atmospheric Observations between 10 and 90 GHz

State-of-the-art microwave radiometers for probing water vapor, temperature and cloud liquid water do not show the high accuracy and stability which is needed for some applications like radio science or the assessment of turbulent weather conditions. Especially scientific experiments, performed in outer-space and missions to investigate other planets, are dependent upon high-precision transmission of data to receivers on Earth passing through the atmosphere, which is a big source of disturbance. Propagation and attenuation at frequencies between a few GHz and several tens of GHz are influenced by dry air as well as by water vapour and liquid water in form of clouds and rain. A precise and stable microwave radiometer to derive these properties has been developed - the Atmospheric Propagation and Profiling System ATPROP.