# Frequency-domain averaging

From AMS Glossary

## frequency-domain averaging

A technique for smoothing the statistical fluctuations in power spectra, thus improving the detectability of signals in noise.

Two essentially equivalent techniques can be used on power spectra derived from

*MN*data points:*M*spectra each containing*N*spectral power density points are averaged together in each frequency bin, producing a single averaged*N*-point spectrum.- The spectral points in a single
*MN*-point spectrum are averaged together in groups of*M*points, also producing a single averaged*N*-point power.

Such techniques are widely used for Doppler spectrum measurements in wind profilers and MST radars.