Intensive concvective phenomena show strong variability in space and time, from tenths to hundreds of meters and from tenths of seconds to minutes. Automatized meteorological networks on the ground are not able to monitor the occurrence and dynamics of these phenomena in sufficient resolution. Atmospheric hydrometeors interfere electromagnetic signal in atmosphere. The magnitude of the interference is relative to the intensity of precipitation. This fact enables us to detect the hydrometeors by monitoring the changes of electromagnetic signal either by active broadcasting of the signal and detecting its part reflected by the hydrometeors or by passive receipt of the signal from different broadcasters. The network of meteorological radars is able to detect mesometeorological phenomena in Slovakia mostly over the level 700-1000 m above ground. The measurement of the hydrometeors, including their dynamics, below this layer by multi-frequency passive radiolocation can bring necessary information in this space.