This paper evaluates mean velocity estimator performance for typical parameter regimes for the 404-MHz National Oceanic and Atmospheric Administration weather radar, the 915-MHz boundary layer profiler, and the 50-MHz mesosphere-stratosphere-troposphere/stratosphere-troposphere radar wind profiling systems. Performance of the velocity estimates is characterized by the fraction of outliers and the standard deviation of the good estimates. For low signal-to-noise ratio, modern estimators generally have better performance than the traditional techniques; however, modern estimators require more information to produce a velocity estimate. The boundary for useful velocity estimates can be determined from the performance curves.¿ 1997 American Geophysical Union