In the early sixties, radar meteorologists acknowledged the potential of retrieving cloud and precipitation properties from Doppler spectra collected from vertically pointing radars. Small scale air turbulence and volume averaged vertical air motion within the radar sampling volume were identified as the primary sources of uncertainty in retrieving cloud and precipitation microphysical information. Since then, several techniques have been proposed, developed and tested for radars operating over a wide range of frequencies. In this paper, a historical overview of the proposed techniques, their assumptions and uncertainties is addressed .Developments in radar hardware, data acquisition, and the use of shorter wavelength radars influenced and promoted distinct advancements in retrieval techniques. This overview includes retrieval techniques developed for radars operating at frequencies extending from VHF to W band. The information included in the Doppler spectra is influenced by the radar temporal and spatial sampling with respect to the scales of cloud and precipitation processes of interest.