Cross-correlation, sharp peak at 0?

1. What does a peak in cross correlation mean?
2. How do you find time delay using cross correlation?

What does a peak in cross correlation mean?

The cross-correlation plot typically produces two peaks: a peak of enrichment corresponding to the predominant fragment length (highest correlation value) and a peak corresponding to the read length (“phantom” peak).

How do you find time delay using cross correlation?

For delay analysis, correlation in the time domain is widely used. The correlation function plots the similarity between two signals for all possible lags τ. The peak of the correlation function occurs at the lag with the best similarity between the two signals, i.e. the estimated delay.