Hi Geoffrey,

Among the special functions you could use in ADE, there is one that directly calculates the psd of a transient signal. It is called just "psd" and it takes care of the autocorrelation calculation you are looking for.
As in the case of a dft, you have to choose the number of points and the type of window.

Hope this helps.

Tosei

Hi Geoffrey,
If you end up needing to do the processing outside ADE, some useful formulas are:
1.Unbiased estimator of correlation(high variance):
R=XX^H, were X it's the vector of samples,H denotes hermitic.
Making the Fourier transform of this will give you the "Periodogram" as estimator.
2.The same estimator but with a reduction in variance(reduces resolution):
R=(1/M)Σ_m=1..MX_mX_m^H, in this expression you divide the samples into M vectors and made an average to reduce variance after transformation.

There exists other estimators but this two are the basic ones that I remember.

If you are doing a wider search you can look for keywords like:Blackman-Tuckey,Welch,Capon,Normalized Capon(Lagunas method),MUSIC or PISARENKO(the two first are Periodograms with modified windowing, the last two ones are called "superesolution estimators" that are good for estimate the frequency of an unknown signal).
Also is worth the effort to look at Matlab since it contains at least the periodogram and welch estimators.
Hope it helps,