Mean frequency determination of narrow-band noise spectra

There are an increasing number of problems involving the detection or measurement of signals which properly comprise noise, but possess certain features distinguishing them physically from homogeneous random noise. The paper deals with the measurement of mean frequency for such a signal whose energy/frequency distribution approximates to a symmetrical Gaussian distribution. The generation of synthetic signal sources for controlled experiments and the design of optimum measuring equipment are described and illustrated by experimental results using a magnetic-amplifier servo loop for automatic measurement. The effect of the signal deviating from its assumed characteristics is also discussed, and it is shown that the measuring equipment described can tolerate a certain amount of signal asymmetry without undue loss of accuracy.