Many times, a key distinction between returns from atmospheric scatterers and those from ground targets is that ground returns have little or no motion. However, ground clutter has other important characteristics that can be used to identify it. Variables used to identify these characteristics include reflectivity texture, clutter phase alignment, and standard deviations of Differential Reflectivity (ZDR) and Differential Phase (phi). These variables are used by the Clutter Mitigation Decision (CMD) algorithm to detect areas of clutter on an elevation-by-elevation, bin-by-bin basis of every volume scan.
Once areas of clutter are identified, the Gaussian Model Adaptive Processing (GMAP) algorithm uses Spectrum Width data to suppress the ground clutter contaminated portion of the signal. Power is removed from the portion of the returned signal within a very narrow width centered at zero velocity. Depending on the availability of returns from meteorological targets outside this width, GMAP rebuilds an estimated weather signal that replaces the initially removed data.