Analysis of CLIWA-NET intensive operation period data as part of the monitoring activities at the German Meteorological Service site Lindenberg

In order to provide accurate observations, methods are developed which enable an automatic quality control of microwave radiometer data. The algorithm includes other continuously available measurements from radiosondes and GPS. The access to accurate observations and a routine evaluation of data quality is required for further applications. Assessment of retrieval accuracy and investigations about the diurnal cycle obtained at Lindenberg are presented to exemplify the usefulness of reference sites as an essential component of any observational program. With respect to cloud liquid water estimates, it is shown that the integrated values are in good agreement with calculations derived from radiosondes. The low-resolution liquid water profiles show deviations in cloud base height, especially for fractional cloudiness.