A technique for precision estimation in analog cross-spectrum measurements
Charles Erwin Cohn · IEEE Transactions on Acoustics Speech and Signal Processing · 1974
The precision of an analog cross-spectrum measurement can be estimated if the product of the two signals is integrated by a voltage-to-frequency converter having separate pulse outputs for positive and negative inputs. The difference between the two pulse counts gives the spectrum reading, while their ratio is used in estimating the precision. Coherence may also be estimated in this way.