What is the physical meaning of the cross-spectrum of two signals measured at two locations and different moment?

1. How do you interpret cross spectral density?
2. What is cross spectrum analysis?
3. What is the cross correlation function corresponding to the cross power density spectrum?
4. What is a spectral moment?

How do you interpret cross spectral density?

A high cross spectral density value indicates the two time domain signals tend to have high power spectral density, while a value of 0 indicates they tend to have unrelated power spectral density. Note that the cross spectral density is a spectrum, so the previous sentence applies at specific frequency values.

What is cross spectrum analysis?

Cross spectral analysis allows one to determine the relationship between two time series as a function of frequency.

What is the cross correlation function corresponding to the cross power density spectrum?

Cross-correlation function is a function that defines the relationship between two random signals. The cross power spectral density, S_xy❲f❳is complex-valued with real and imaginary parts given by co spectrum ❲Co_xy❲f❳❳and quadrature spectrum ❲Qu_xy❲f❳❳respectively.

What is a spectral moment?

A spectral moment method is proposed to characterize the turbulence energy spectra in the wavevector and frequency domain in the lowest-order sense. The frequency shift velocity and the random sweeping velocity are obtained from the first-order and second-order moments of the wavenumber–frequency spectra.