Cross correlation fft

1. Does cross-correlation use FFT?
2. What is cross-correlation in frequency domain?
3. What is cross-correlation in signals?
4. What is cross-correlation in time series?

Does cross-correlation use FFT?

The calculation of the cross-correlation function using FFT is a well-known method for measuring correlation and time delay or shift between 1D and 2D signals in fields such as audio and image analysis.

What is cross-correlation in frequency domain?

According to the cross-correlation theorem : the cross-correlation between two signals is equal to the product of fourier transform of one signal multiplied by complex conjugate of fourier transform of another signal.

What is cross-correlation in signals?

In signal processing, cross-correlation is a measure of similarity of two series as a function of the displacement of one relative to the other. This is also known as a sliding dot product or sliding inner-product. It is commonly used for searching a long signal for a shorter, known feature.

What is cross-correlation in time series?

Cross correlation presents a technique for comparing two time series and finding objectively how they match up with each other, and in particular where the best match occurs. It can also reveal any periodicities in the data.