Welch method window

1. What does the Welch method do?
2. Which windowing technique is best?
3. Why use Welch PSD?
4. Which method in windowing has the least amount of distortion?

What does the Welch method do?

Welch's technique to reduce the variance of the periodogram breaks the time series into segments, usually overlapping. Welch's method computes a modified periodogram for each segment and then averages these estimates to produce the estimate of the power spectral density.

Which windowing technique is best?

The Hamming window is preferred by many due to its relatively narrow main lobe width and good attenuation of the first few side lobes.

Why use Welch PSD?

Welch's method is an improvement on the standard periodogram spectrum estimating method and on Bartlett's method, in that it reduces noise in the estimated power spectra in exchange for reducing the frequency resolution.

Which method in windowing has the least amount of distortion?

The rectangular window is the optimal choice if the user can choose a window length with no signal discontinuities. This window does not distort the spectral representation of the signal when there are no discontinuities.