This thesis focuses on the operational data of the Microwave humidity sounders Special Sensor Microwave Temperature (SSMT-2), Advanced Microwave Sounding Unit - B (AMSU-B) and Microwave Humidity Sounder (MHS) on board polar orbiting satellites. Since these instruments were not designed for climate monitoring, their data sets do not fulfil the requirements for this purpose. To obtain a data record usable for climate monitoring, inter-satellite biases need to be understood and, ideally, removed. A data record for climate research should also be free from operational artefacts, such as doubled data. Also, a consistent format and a data frame containing a single orbit without any overlap with the preceding or succeeding orbit is desirable. Furthermore, the uncertainties within the measurement process need to be characterised and propagated to the fundamental measurand in the data set, which is the brightness temperature or radiance. This information would allow for constructing an uncertainty quantified fundamental climate data record (FCDR) of brightness temperatures as it is required for obtaining sound results in climate research.