A new method to estimate the Doppler spectrum parameters of atmospheric signals based on adaptive filtering is presented. The new method is compared with the traditional FFT-based method. In order to do so both methods have been applied to process the same atmospheric data set obtained by the FM-CW polarimetric Doppler radar TARA (Transportable Atmospheric Radar) developed by IRCTR. In section 2 the adaptive filtering processing is described. The details of the FFT-based algorithm will not be described. The reader is referred to Doviak and Zrnic (1993) for an extensive discussion. Section 3 describes the practical implementation of both algoritms in the radar. In section 4 the results of both algorithms are discussed and compared. Section 5 outlines the advantages and disadvantages of both methods.@en