General remarks
Meteorological observations from space started more than 50 years ago with the launch of Tiros I in 1960. Satellite instruments and observation techniques have changed dramatically since then, making time series of satellite data very inhomogeneous and causing their availability to vary across different regions. Using various assimilation techniques, it is possible to compile regional and global climate datasets based on satellite data. However, before applying satellite data for climatological assessments it is important to reduce the number of gaps in the data and validate satellite data with ground measurements.