Howtosignalprocessing
Why detrend before fft?
Detrending the signal makes this > approximation better: the DFT acts as if it's signal "wraps around" from > the Nth data point to the first -- so if there's a big mismatch at that > point, the DFT will "see" signal components from the discontinuity.
What is a Detrended signal?
What is Detrending? Removal of trends from a time series data set is called detrend. It allows us to know about the normal cyclic trend and the trend beyond the cycle. Detrending can be done using many statistical techniques such as quadratic detrending, linear trending, Baxter-King filter etc.
