The potential of ground-based remote sensing for vertically profiling atmospheric dynamics and thermodynamics has been known for decades. But while enormous amounts of money have been (successfully) invested in satellite remote sensing of the atmosphere, the ground-based component has been basically neglected, although both approaches deliver complementary information: satellites mostly from the mid to high troposphere and ground-based profiling instruments mainly from the atmospheric boundary layer. Recently, instruments such as ground-based cloud radars, microwave radiometers and Doppler lidars have reached a point of maturity to be operated continuously in operational networks. Increased sensitivity, higher stability and more reliable calibrations make retrievals of more accurate than just a few years ago. However, better operational performance does not reduce uncertainties due to physical realities: one remote sensing instrument alone will never be capable of profiling the complete troposphere. Synergetic retrievals using simultaneous observations at different wavelengths in active and passive mode show a significant increase in information content and need to be further exploited in future. Currently, the development of retrieval schemes for classifying the boundary layer and cloud type from synergetic observations are in the center of research focus.