To reduce uncertainty from a single measurement point, averaging can be used. Averaging over several measurements smooths out the phase noise trace to give a more realistic phase noise measurement at any given frequency offset. When averaging is enabled, cross correlation can also be adjusted. Correlation measures the input signal against different reference sources. Since the noise profiles of the different reference sources are correlated, the reference noise is subtracted out and the resulting measurement is a better representation of the signal rather than noise from the measurement equipment. Increasing the correlation is especially important when measuring the noise floor of a very clean clock source.