It is used in physics, engineering, and applied mathematics for estimating the power of a signal at different frequencies.
The method is based on the concept of using periodogram spectrum estimates, which are the result of converting a signal from the time domain to the frequency domain.
The Welch method is based on Bartlett's method and differs in two ways: After doing the above, the periodogram is calculated by computing the discrete Fourier transform, and then computing the squared magnitude of the result, yielding power spectrum estimates for each segment.
The end result is an array of power measurements vs. frequency "bin".
Other overlapping windowed Fourier transforms include: